def main():
    i, j, k, l = symbols('i,j,k,l', below_fermi=True)
    a, b, c, d = symbols('a,b,c,d', above_fermi=True)
    H1, H2 = getHamiltonian()
    eq_H1 = computeHausdorff(H1)  #e^(-T)H1e^T
    eq_H2 = computeHausdorff(H2)
    print("CC energy:")
    Energy = wicks(eq_H1 + eq_H2,
                   simplify_dummies=True,
                   keep_only_fully_contracted=True,
                   simplify_kronecker_deltas=True)
    Energy = substitute_dummies(Energy,
                                new_indices=True,
                                pretty_indices=pretty_dummies_dict)
    print(latex(Energy))
    print()
    """
    print("CC dE_H1/(dLia):")
    eqH1T1 = wicks(Fd(i)*F(a)*eq_H1, simplify_dummies=True, keep_only_fully_contracted=True, simplify_kronecker_deltas=True)
    P = PermutationOperator
    eqH1T1 = simplify_index_permutations(eqH1T1, [P(a, b), P(i, j)])
    eqH1T1 = substitute_dummies(eqH1T1,new_indices=True, pretty_indices=pretty_dummies_dict)
    print(latex(eqH1T1))
    print() 

	print("CC dE_H2/(dLia):")
	eqH2T1 = wicks(Fd(i)*F(a)*eq_H2, simplify_dummies=True, keep_only_fully_contracted=True, simplify_kronecker_deltas=True)
	P = PermutationOperator
	eqH2T1 = simplify_index_permutations(eqH2T1, [P(a, b), P(i, j)])
	eqH2T1 = substitute_dummies(eqH2T1,new_indices=True, pretty_indices=pretty_dummies_dict)
	print(latex(eqH2T1))
	print()
    """

    print("CC dE_H1/(dLijab):")
    eqH1T2 = wicks(Fd(j) * F(b) * Fd(i) * F(a) * eq_H1,
                   simplify_dummies=True,
                   keep_only_fully_contracted=True,
                   simplify_kronecker_deltas=True)
    P = PermutationOperator
    eqH1T2 = simplify_index_permutations(eqH1T2, [P(a, b), P(i, j)])
    eqH1T2 = substitute_dummies(eqH1T2,
                                new_indices=True,
                                pretty_indices=pretty_dummies_dict)
    print(latex(eqH1T2))
    print()

    print("CC dE_H2/(dLijab):")
    eqH2T2 = wicks(Fd(j) * F(b) * Fd(i) * F(a) * eq_H2,
                   simplify_dummies=True,
                   keep_only_fully_contracted=True,
                   simplify_kronecker_deltas=True)
    P = PermutationOperator
    eqH2T2 = simplify_index_permutations(eqH2T2, [P(i, j), P(a, b)])
    eqH2T2 = substitute_dummies(eqH2T2,
                                new_indices=True,
                                pretty_indices=pretty_dummies_dict)
    print(latex(eqH2T2))
    print()
Exemplo n.º 2
0
def OPDM(L, R, flavor):

    display(
        Markdown(
            rf""" Computing OPDM for {flavor} (skipping summation for dummy variables)"""
        ))

    i, j = symbols('i,j', below_fermi=True)
    a, b = symbols('a,b', above_fermi=True)

    PermutList = [PermutationOperator(i, j), PermutationOperator(a, b)]

    oo = Fd(i) * F(j)
    cc = BCH.level(oo, "SD")
    g_oo = evaluate_deltas(wicks(L * cc * R, keep_only_fully_contracted=True))
    g_oo = simplify_index_permutations(g_oo, PermutList)
    index_rule = {'below': 'klmno', 'above': 'abcde'}
    g_oo = substitute_dummies(g_oo,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_{ij}')
    final_eq = Eq(gamma, g_oo)
    display(final_eq)

    ov = Fd(i) * F(a)
    cc = BCH.level(ov, "SD")
    g_ov = evaluate_deltas(wicks(L * cc * R, keep_only_fully_contracted=True))
    g_ov = simplify_index_permutations(g_ov, PermutList)
    index_rule = {'below': 'jklmn', 'above': 'bcdef'}
    g_ov = substitute_dummies(g_ov,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_{ia}')
    final_eq = Eq(gamma, g_ov)
    display(final_eq)

    vo = Fd(a) * F(i)
    cc = BCH.level(vo, "SD")
    g_vo = evaluate_deltas(wicks(L * cc * R, keep_only_fully_contracted=True))
    g_vo = simplify_index_permutations(g_vo, PermutList)
    index_rule = {'below': 'jklmn', 'above': 'bcdef'}
    g_vo = substitute_dummies(g_vo,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_{ai}')
    final_eq = Eq(gamma, g_vo)
    display(final_eq)

    vv = Fd(a) * F(b)
    cc = BCH.level(vv, "SD")
    g_vv = evaluate_deltas(wicks(L * cc * R, keep_only_fully_contracted=True))
    g_vv = simplify_index_permutations(g_vv, PermutList)
    index_rule = {'below': 'ijklm', 'above': 'cdefg'}
    g_vv = substitute_dummies(g_vv,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_{ab}')
    final_eq = Eq(gamma, g_vv)
    display(final_eq)
Exemplo n.º 3
0
def OPTDM(Lf1, Rf1, Lf2, Rf2, flavor1, flavor2):

    display(
        Markdown(
            rf""" Computing Dyson OPTDM between {flavor1} $\rightarrow$ {flavor2} (skipping summation for dummy variables)"""
        ))

    i = symbols('i', below_fermi=True)
    a = symbols('a', above_fermi=True)

    index_rule = {'below': 'jklmn', 'above': 'bcde'}

    oo = Fd(i)
    cc = BCH.level(oo, "SD")
    g_oo = evaluate_deltas(
        wicks(Lf2 * cc * Rf1, keep_only_fully_contracted=True))
    g_oo = substitute_dummies(g_oo,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_i^{R}')
    final_eq = Eq(gamma, g_oo)
    display(final_eq)

    ov = Fd(a)
    cc = BCH.level(ov, "SD")
    g_ov = evaluate_deltas(
        wicks(Lf2 * cc * Rf1, keep_only_fully_contracted=True))
    index_rule = {'below': 'jklmn', 'above': 'bcdef'}
    g_ov = substitute_dummies(g_ov,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_a^{R}')
    final_eq = Eq(gamma, g_ov)
    display(final_eq)

    vo = F(i)
    cc = BCH.level(vo, "SD")
    g_vo = evaluate_deltas(
        wicks(Lf1 * cc * Rf2, keep_only_fully_contracted=True))
    index_rule = {'below': 'jklmn', 'above': 'bcdef'}
    g_vo = substitute_dummies(g_vo,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_i^{L}')
    final_eq = Eq(gamma, g_vo)
    display(final_eq)

    vv = F(a)
    cc = BCH.level(vv, "SD")
    g_vv = evaluate_deltas(
        wicks(Lf1 * cc * Rf2, keep_only_fully_contracted=True))
    index_rule = {'below': 'ijklm', 'above': 'cdefg'}
    g_vv = substitute_dummies(g_vv,
                              new_indices=True,
                              pretty_indices=index_rule)
    gamma = Symbol('\gamma_a^{L}')
    final_eq = Eq(gamma, g_vv)
    display(final_eq)
Exemplo n.º 4
0
def test_fully_contracted():
    i, j, k, l = symbols("i j k l", below_fermi=True)
    a, b, c, d = symbols("a b c d", above_fermi=True)
    p, q, r, s = symbols("p q r s", cls=Dummy)

    Fock = AntiSymmetricTensor("f", (p,), (q,)) * NO(Fd(p) * F(q))
    V = (AntiSymmetricTensor("v", (p, q), (r, s)) * NO(Fd(p) * Fd(q) * F(s) * F(r))) / 4

    Fai = wicks(NO(Fd(i) * F(a)) * Fock, keep_only_fully_contracted=True, simplify_kronecker_deltas=True)
    assert Fai == AntiSymmetricTensor("f", (a,), (i,))
    Vabij = wicks(NO(Fd(i) * Fd(j) * F(b) * F(a)) * V, keep_only_fully_contracted=True, simplify_kronecker_deltas=True)
    assert Vabij == AntiSymmetricTensor("v", (a, b), (i, j))
Exemplo n.º 5
0
def test_wicks():
    p, q, r, s = symbols("p,q,r,s", above_fermi=True)

    # Testing for particles only

    str = F(p) * Fd(q)
    assert wicks(str) == NO(F(p) * Fd(q)) + KroneckerDelta(p, q)
    str = Fd(p) * F(q)
    assert wicks(str) == NO(Fd(p) * F(q))

    str = F(p) * Fd(q) * F(r) * Fd(s)
    nstr = wicks(str)
    fasit = NO(
        KroneckerDelta(p, q) * KroneckerDelta(r, s)
        + KroneckerDelta(p, q) * AnnihilateFermion(r) * CreateFermion(s)
        + KroneckerDelta(r, s) * AnnihilateFermion(p) * CreateFermion(q)
        - KroneckerDelta(p, s) * AnnihilateFermion(r) * CreateFermion(q)
        - AnnihilateFermion(p)
        * AnnihilateFermion(r)
        * CreateFermion(q)
        * CreateFermion(s)
    )
    assert nstr == fasit

    assert (p * q * nstr).expand() == wicks(p * q * str)
    assert (nstr * p * q * 2).expand() == wicks(str * p * q * 2)

    # Testing CC equations particles and holes
    i, j, k, l = symbols("i j k l", below_fermi=True, cls=Dummy)
    a, b, c, d = symbols("a b c d", above_fermi=True, cls=Dummy)
    p, q, r, s = symbols("p q r s", cls=Dummy)

    assert wicks(F(a) * NO(F(i) * F(j)) * Fd(b)) == NO(
        F(a) * F(i) * F(j) * Fd(b)
    ) + KroneckerDelta(a, b) * NO(F(i) * F(j))
    assert wicks(F(a) * NO(F(i) * F(j) * F(k)) * Fd(b)) == NO(
        F(a) * F(i) * F(j) * F(k) * Fd(b)
    ) - KroneckerDelta(a, b) * NO(F(i) * F(j) * F(k))

    expr = wicks(Fd(i) * NO(Fd(j) * F(k)) * F(l))
    assert expr == -KroneckerDelta(i, k) * NO(Fd(j) * F(l)) - KroneckerDelta(j, l) * NO(
        Fd(i) * F(k)
    ) - KroneckerDelta(i, k) * KroneckerDelta(j, l) + KroneckerDelta(i, l) * NO(
        Fd(j) * F(k)
    ) + NO(
        Fd(i) * Fd(j) * F(k) * F(l)
    )
    expr = wicks(F(a) * NO(F(b) * Fd(c)) * Fd(d))
    assert expr == -KroneckerDelta(a, c) * NO(F(b) * Fd(d)) - KroneckerDelta(b, d) * NO(
        F(a) * Fd(c)
    ) - KroneckerDelta(a, c) * KroneckerDelta(b, d) + KroneckerDelta(a, d) * NO(
        F(b) * Fd(c)
    ) + NO(
        F(a) * F(b) * Fd(c) * Fd(d)
    )
Exemplo n.º 6
0
def test_NO():
    i, j, k, l = symbols('i j k l', below_fermi=True)
    a, b, c, d = symbols('a b c d', above_fermi=True)
    p, q, r, s = symbols('p q r s', cls=Dummy)

    assert (NO(Fd(p)*F(q) + Fd(a)*F(b)) ==
       NO(Fd(p)*F(q)) + NO(Fd(a)*F(b)))
    assert (NO(Fd(i)*NO(F(j)*Fd(a))) ==
       NO(Fd(i)*F(j)*Fd(a)))
    assert NO(1) == 1
    assert NO(i) == i
    assert (NO(Fd(a)*Fd(b)*(F(c) + F(d))) ==
            NO(Fd(a)*Fd(b)*F(c)) +
            NO(Fd(a)*Fd(b)*F(d)))

    assert NO(Fd(a)*F(b))._remove_brackets() == Fd(a)*F(b)
    assert NO(F(j)*Fd(i))._remove_brackets() == F(j)*Fd(i)

    assert (NO(Fd(p)*F(q)).subs(Fd(p), Fd(a) + Fd(i)) ==
            NO(Fd(a)*F(q)) + NO(Fd(i)*F(q)))
    assert (NO(Fd(p)*F(q)).subs(F(q), F(a) + F(i)) ==
            NO(Fd(p)*F(a)) + NO(Fd(p)*F(i)))

    expr = NO(Fd(p)*F(q))._remove_brackets()
    assert wicks(expr) == NO(expr)

    assert NO(Fd(a)*F(b)) == - NO(F(b)*Fd(a))

    no = NO(Fd(a)*F(i)*F(b)*Fd(j))
    l1 = [ ind for ind in no.iter_q_creators() ]
    assert l1 == [0, 1]
    l2 = [ ind for ind in no.iter_q_annihilators() ]
    assert l2 == [3, 2]
Exemplo n.º 7
0
def test_NO():
    i, j, k, l = symbols('i j k l', below_fermi=True)
    a, b, c, d = symbols('a b c d', above_fermi=True)
    p, q, r, s = symbols('p q r s', cls=Dummy)

    assert (NO(Fd(p) * F(q) + Fd(a) * F(b)) == NO(Fd(p) * F(q)) +
            NO(Fd(a) * F(b)))
    assert (NO(Fd(i) * NO(F(j) * Fd(a))) == NO(Fd(i) * F(j) * Fd(a)))
    assert NO(1) == 1
    assert NO(i) == i
    assert (NO(Fd(a) * Fd(b) * (F(c) + F(d))) == NO(Fd(a) * Fd(b) * F(c)) +
            NO(Fd(a) * Fd(b) * F(d)))

    assert NO(Fd(a) * F(b))._remove_brackets() == Fd(a) * F(b)
    assert NO(F(j) * Fd(i))._remove_brackets() == F(j) * Fd(i)

    assert (NO(Fd(p) * F(q)).subs(Fd(p),
                                  Fd(a) + Fd(i)) == NO(Fd(a) * F(q)) +
            NO(Fd(i) * F(q)))
    assert (NO(Fd(p) * F(q)).subs(F(q),
                                  F(a) + F(i)) == NO(Fd(p) * F(a)) +
            NO(Fd(p) * F(i)))

    expr = NO(Fd(p) * F(q))._remove_brackets()
    assert wicks(expr) == NO(expr)

    assert NO(Fd(a) * F(b)) == -NO(F(b) * Fd(a))

    no = NO(Fd(a) * F(i) * F(b) * Fd(j))
    l1 = [ind for ind in no.iter_q_creators()]
    assert l1 == [0, 1]
    l2 = [ind for ind in no.iter_q_annihilators()]
    assert l2 == [3, 2]
Exemplo n.º 8
0
def test_wicks():
    p,q,r,s = symbols('pqrs',above_fermi=True)

    # Testing for particles only

    str = F(p)*Fd(q)
    assert wicks(str) == NO(F(p)*Fd(q)) + KroneckerDelta(p,q)
    str = Fd(p)*F(q)
    assert wicks(str) == NO(Fd(p)*F(q))


    str = F(p)*Fd(q)*F(r)*Fd(s)
    nstr= wicks(str)
    fasit = NO(
    KroneckerDelta(p, q)*KroneckerDelta(r, s)
    + KroneckerDelta(p, q)*AnnihilateFermion(r)*CreateFermion(s)
    + KroneckerDelta(r, s)*AnnihilateFermion(p)*CreateFermion(q)
    - KroneckerDelta(p, s)*AnnihilateFermion(r)*CreateFermion(q)
    - AnnihilateFermion(p)*AnnihilateFermion(r)*CreateFermion(q)*CreateFermion(s))
    assert nstr == fasit

    assert (p*q*nstr).expand() == wicks(p*q*str)
    assert (nstr*p*q*2).expand() == wicks(str*p*q*2)


    # Testing CC equations particles and holes
    i,j,k,l = symbols('ijkl',below_fermi=True,dummy=True)
    a,b,c,d = symbols('abcd',above_fermi=True,dummy=True)
    p,q,r,s = symbols('pqrs',dummy=True)

    assert (wicks(F(a)*NO(F(i)*F(j))*Fd(b)) ==
            NO(F(a)*F(i)*F(j)*Fd(b)) +
            KroneckerDelta(a,b)*NO(F(i)*F(j)))
    assert (wicks(F(a)*NO(F(i)*F(j)*F(k))*Fd(b)) ==
            NO(F(a)*F(i)*F(j)*F(k)*Fd(b)) -
            KroneckerDelta(a,b)*NO(F(i)*F(j)*F(k)))


    expr = wicks(Fd(i)*NO(Fd(j)*F(k))*F(l))
    assert (expr ==
           -KroneckerDelta(i,k)*NO(Fd(j)*F(l)) -
            KroneckerDelta(j,l)*NO(Fd(i)*F(k)) -
            KroneckerDelta(i,k)*KroneckerDelta(j,l)+
            KroneckerDelta(i,l)*NO(Fd(j)*F(k)) +
            NO(Fd(i)*Fd(j)*F(k)*F(l)))
    expr = wicks(F(a)*NO(F(b)*Fd(c))*Fd(d))
    assert (expr ==
           -KroneckerDelta(a,c)*NO(F(b)*Fd(d)) -
            KroneckerDelta(b,d)*NO(F(a)*Fd(c)) -
            KroneckerDelta(a,c)*KroneckerDelta(b,d)+
            KroneckerDelta(a,d)*NO(F(b)*Fd(c)) +
            NO(F(a)*F(b)*Fd(c)*Fd(d)))
Exemplo n.º 9
0
def test_fully_contracted():
    i, j, k, l = symbols('i j k l', below_fermi=True)
    a, b, c, d = symbols('a b c d', above_fermi=True)
    p, q, r, s = symbols('p q r s', cls=Dummy)

    Fock = (AntiSymmetricTensor('f', (p, ), (q, )) * NO(Fd(p) * F(q)))
    V = (AntiSymmetricTensor('v', (p, q),
                             (r, s)) * NO(Fd(p) * Fd(q) * F(s) * F(r))) / 4

    Fai = wicks(NO(Fd(i) * F(a)) * Fock,
                keep_only_fully_contracted=True,
                simplify_kronecker_deltas=True)
    assert Fai == AntiSymmetricTensor('f', (a, ), (i, ))
    Vabij = wicks(NO(Fd(i) * Fd(j) * F(b) * F(a)) * V,
                  keep_only_fully_contracted=True,
                  simplify_kronecker_deltas=True)
    assert Vabij == AntiSymmetricTensor('v', (a, b), (i, j))
def get_two_body_equation(equation_h, equation_u):
    two_body_eq = wicks(
        Fd(j) * F(b) * Fd(i) * F(a) * equation_u, **wicks_kwargs)

    p = PermutationOperator
    two_body_eq = simplify_index_permutations(two_body_eq, [p(i, j), p(a, b)])
    two_body_eq = substitute_dummies(two_body_eq, **sub_kwargs)

    return two_body_eq
def get_one_body_equation(equation_h, equation_u):
    one_body_eq = wicks(
        Fd(j) * F(b) * Fd(i) * F(a) * equation_h, **wicks_kwargs)

    p = PermutationOperator
    one_body_eq = simplify_index_permutations(one_body_eq, [p(a, b), p(i, j)])
    one_body_eq = substitute_dummies(one_body_eq, **sub_kwargs)

    return one_body_eq
Exemplo n.º 12
0
def level(H, expr):

    pretty_dummies_dict = {
        'above': 'defg',
        'below': 'lmno',
        'general': 'pqrst'
    }

    #display(Markdown
    #    (rf"""Calculating 4 nested commutators"""))
    C = Commutator

    T1, T2 = get_CC_operators()
    T = T1 + T2
    comm1 = wicks(C(H, T))
    comm1 = evaluate_deltas(comm1)
    comm1 = substitute_dummies(comm1)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    comm2 = wicks(C(comm1, T))
    comm2 = evaluate_deltas(comm2)
    comm2 = substitute_dummies(comm2)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    comm3 = wicks(C(comm2, T))
    comm3 = evaluate_deltas(comm3)
    comm3 = substitute_dummies(comm3)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    comm4 = wicks(C(comm3, T))
    comm4 = evaluate_deltas(comm4)
    comm4 = substitute_dummies(comm4)

    eq = H + comm1 + comm2 / 2 + comm3 / 6 + comm4 / 24
    eq = eq.expand()
    eq = evaluate_deltas(eq)
    eq = substitute_dummies(eq,
                            new_indices=True,
                            pretty_indices=pretty_dummies_dict)

    return eq
def computeHausdorff(H):

    print("Calculating 4 nested commutators")
    C = Commutator

    T1, T2 = get_T_operators()
    T = T2
    print("commutator 1...")
    comm1 = wicks(C(H, T))
    comm1 = evaluate_deltas(comm1)
    comm1 = substitute_dummies(comm1)

    T1, T2 = get_T_operators()
    T = T2
    print("commutator 2...")
    comm2 = wicks(C(comm1, T))
    comm2 = evaluate_deltas(comm2)
    comm2 = substitute_dummies(comm2)

    T1, T2 = get_T_operators()
    T = T2
    print("commutator 3...")
    comm3 = wicks(C(comm2, T))
    comm3 = evaluate_deltas(comm3)
    comm3 = substitute_dummies(comm3)

    T1, T2 = get_T_operators()
    T = T2
    print("commutator 4...")
    comm4 = wicks(C(comm3, T))
    comm4 = evaluate_deltas(comm4)
    comm4 = substitute_dummies(comm4)

    print("construct Hausdorff expansion...")
    eq = H + comm1 + comm2 / 2 + comm3 / 6 + comm4 / 24
    eq = eq.expand()
    eq = evaluate_deltas(eq)
    eq = substitute_dummies(eq,
                            new_indices=True,
                            pretty_indices=pretty_dummies_dict)
    print("*********************")
    print()
    return eq
def compute_hausdorff(h, cluster_func, num_terms=4):
    commutator = Commutator
    comm_term = h

    equation = comm_term

    for i in range(num_terms):
        t = sum(cluster_func())

        comm_term = wicks(commutator(comm_term, t))
        comm_term = substitute_dummies(evaluate_deltas(comm_term))

        equation += comm_term / factorial(i + 1)

    equation = equation.expand()
    equation = evaluate_deltas(equation)
    equation = substitute_dummies(equation,
                                  new_indices=True,
                                  pretty_indices=pretty_dummies)

    return equation
Exemplo n.º 15
0
def test_NO():
    i, j, k, l = symbols('i j k l', below_fermi=True)
    a, b, c, d = symbols('a b c d', above_fermi=True)
    p, q, r, s = symbols('p q r s', cls=Dummy)

    assert (NO(Fd(p)*F(q) + Fd(a)*F(b)) ==
       NO(Fd(p)*F(q)) + NO(Fd(a)*F(b)))
    assert (NO(Fd(i)*NO(F(j)*Fd(a))) ==
       NO(Fd(i)*F(j)*Fd(a)))
    assert NO(1) == 1
    assert NO(i) == i
    assert (NO(Fd(a)*Fd(b)*(F(c) + F(d))) ==
            NO(Fd(a)*Fd(b)*F(c)) +
            NO(Fd(a)*Fd(b)*F(d)))

    assert NO(Fd(a)*F(b))._remove_brackets() == Fd(a)*F(b)
    assert NO(F(j)*Fd(i))._remove_brackets() == F(j)*Fd(i)

    assert (NO(Fd(p)*F(q)).subs(Fd(p), Fd(a) + Fd(i)) ==
            NO(Fd(a)*F(q)) + NO(Fd(i)*F(q)))
    assert (NO(Fd(p)*F(q)).subs(F(q), F(a) + F(i)) ==
            NO(Fd(p)*F(a)) + NO(Fd(p)*F(i)))

    expr = NO(Fd(p)*F(q))._remove_brackets()
    assert wicks(expr) == NO(expr)

    assert NO(Fd(a)*F(b)) == - NO(F(b)*Fd(a))

    no = NO(Fd(a)*F(i)*F(b)*Fd(j))
    l1 = [ ind for ind in no.iter_q_creators() ]
    assert l1 == [0, 1]
    l2 = [ ind for ind in no.iter_q_annihilators() ]
    assert l2 == [3, 2]
    no = NO(Fd(a)*Fd(i))
    assert no.has_q_creators == 1
    assert no.has_q_annihilators == -1
    assert str(no) == ':CreateFermion(a)*CreateFermion(i):'
    assert repr(no) == 'NO(CreateFermion(a)*CreateFermion(i))'
    assert latex(no) == r'\left\{a^\dagger_{a} a^\dagger_{i}\right\}'
    raises(NotImplementedError, lambda:  NO(Bd(p)*F(q)))
Exemplo n.º 16
0
def test_NO():
    i, j, k, l = symbols("i j k l", below_fermi=True)
    a, b, c, d = symbols("a b c d", above_fermi=True)
    p, q, r, s = symbols("p q r s", cls=Dummy)

    assert NO(Fd(p) * F(q) + Fd(a) * F(b)) == NO(Fd(p) * F(q)) + NO(Fd(a) * F(b))
    assert NO(Fd(i) * NO(F(j) * Fd(a))) == NO(Fd(i) * F(j) * Fd(a))
    assert NO(1) == 1
    assert NO(i) == i
    assert NO(Fd(a) * Fd(b) * (F(c) + F(d))) == NO(Fd(a) * Fd(b) * F(c)) + NO(
        Fd(a) * Fd(b) * F(d)
    )

    assert NO(Fd(a) * F(b))._remove_brackets() == Fd(a) * F(b)
    assert NO(F(j) * Fd(i))._remove_brackets() == F(j) * Fd(i)

    assert NO(Fd(p) * F(q)).subs(Fd(p), Fd(a) + Fd(i)) == NO(Fd(a) * F(q)) + NO(
        Fd(i) * F(q)
    )
    assert NO(Fd(p) * F(q)).subs(F(q), F(a) + F(i)) == NO(Fd(p) * F(a)) + NO(
        Fd(p) * F(i)
    )

    expr = NO(Fd(p) * F(q))._remove_brackets()
    assert wicks(expr) == NO(expr)

    assert NO(Fd(a) * F(b)) == -NO(F(b) * Fd(a))

    no = NO(Fd(a) * F(i) * F(b) * Fd(j))
    l1 = [ind for ind in no.iter_q_creators()]
    assert l1 == [0, 1]
    l2 = [ind for ind in no.iter_q_annihilators()]
    assert l2 == [3, 2]
    no = NO(Fd(a) * Fd(i))
    assert no.has_q_creators == 1
    assert no.has_q_annihilators == -1
    assert str(no) == ":CreateFermion(a)*CreateFermion(i):"
    assert repr(no) == "NO(CreateFermion(a)*CreateFermion(i))"
    assert latex(no) == r"\left\{a^\dagger_{a} a^\dagger_{i}\right\}"
    raises(NotImplementedError, lambda: NO(Bd(p) * F(q)))
Exemplo n.º 17
0
#Setup Hamiltonian, not on normal order form
h = AntiSymmetricTensor('h', (p, ), (q, ))
pq = ap_dagger * aq

V = AntiSymmetricTensor('V', (p, q), (r, s))
pqsr = Fd(p) * Fd(q) * F(s) * F(r)

H0 = h * pq
HI = Rational(1, 4) * V * pqsr

H = H0 + HI

#Compute the normal ordered form of the Hamiltonian
#sympy.physics.secondquant.wicks(e, **kw_args)[source]
#Returns the normal ordered equivalent of an expression using Wicks Theorem
H_N = evaluate_deltas(wicks(H))
H_N = substitute_dummies(H_N,
                         new_indices=True,
                         pretty_indices=pretty_dummies_dict)

Eref = evaluate_deltas(wicks(H, keep_only_fully_contracted=True))
Eref = substitute_dummies(Eref,
                          new_indices=True,
                          pretty_indices=pretty_dummies_dict)

print("Eref: ", latex(Eref))
print()
print("Normal ordered Hamiltonian")
print(latex(H_N))
print()
Exemplo n.º 18
0
def main():
    print()
    print("Calculates the Coupled-Cluster energy- and amplitude equations")
    print("See 'An Introduction to Coupled Cluster Theory' by")
    print("T. Daniel Crawford and Henry F. Schaefer III")
    print("http://www.ccc.uga.edu/lec_top/cc/html/review.html")
    print()

    # setup hamiltonian
    p, q, r, s = symbols('p,q,r,s', cls=Dummy)
    f = AntiSymmetricTensor('f', (p,), (q,))
    pr = NO((Fd(p)*F(q)))
    v = AntiSymmetricTensor('v', (p, q), (r, s))
    pqsr = NO(Fd(p)*Fd(q)*F(s)*F(r))

    H = f*pr + Rational(1, 4)*v*pqsr
    print("Using the hamiltonian:", latex(H))

    print("Calculating 4 nested commutators")
    C = Commutator

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 1...")
    comm1 = wicks(C(H, T))
    comm1 = evaluate_deltas(comm1)
    comm1 = substitute_dummies(comm1)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 2...")
    comm2 = wicks(C(comm1, T))
    comm2 = evaluate_deltas(comm2)
    comm2 = substitute_dummies(comm2)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 3...")
    comm3 = wicks(C(comm2, T))
    comm3 = evaluate_deltas(comm3)
    comm3 = substitute_dummies(comm3)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 4...")
    comm4 = wicks(C(comm3, T))
    comm4 = evaluate_deltas(comm4)
    comm4 = substitute_dummies(comm4)

    print("construct Hausdoff expansion...")
    eq = H + comm1 + comm2/2 + comm3/6 + comm4/24
    eq = eq.expand()
    eq = evaluate_deltas(eq)
    eq = substitute_dummies(eq, new_indices=True,
            pretty_indices=pretty_dummies_dict)
    print("*********************")
    print()

    print("extracting CC equations from full Hbar")
    i, j, k, l = symbols('i,j,k,l', below_fermi=True)
    a, b, c, d = symbols('a,b,c,d', above_fermi=True)
    print()
    print("CC Energy:")
    print(latex(wicks(eq, simplify_dummies=True,
        keep_only_fully_contracted=True)))
    print()
    print("CC T1:")
    eqT1 = wicks(NO(Fd(i)*F(a))*eq, simplify_kronecker_deltas=True, keep_only_fully_contracted=True)
    eqT1 = substitute_dummies(eqT1)
    print(latex(eqT1))
    print()
    print("CC T2:")
    eqT2 = wicks(NO(Fd(i)*Fd(j)*F(b)*F(a))*eq, simplify_dummies=True, keep_only_fully_contracted=True, simplify_kronecker_deltas=True)
    P = PermutationOperator
    eqT2 = simplify_index_permutations(eqT2, [P(a, b), P(i, j)])
    print(latex(eqT2))
Exemplo n.º 19
0
from sympy.physics.secondquant import Commutator, F, Fd, wicks, NO
from sympy import symbols, simplify

a = symbols("b0:8")
exp = F(a[1])*F(a[0])*Fd(a[3])*Fd(a[2]) * F(a[4])*F(a[5])*Fd(a[6])*Fd(a[7])


exp = wicks(exp)
print(exp)
Exemplo n.º 20
0
V = AntiSymmetricTensor('V', (p, q), (r, s))
pqsr = NO(Fd(p) * Fd(q) * F(s) * F(r))

HI = Rational(1, 4) * V * pqsr

HN = E0 + F + HI

i, j, k, l = symbols('i,j,k,l', below_fermi=True)
a, b, c, d = symbols('a,b,c,d', above_fermi=True)

print("Compute CCD energy and amplitude equations term by term")
#BCH: HN + [HN,T] + 0.5*[[HN,T],T] + 1/6 * [[[HN,T],T],T] + 1/24 * [[[[HN,T],T],T],T]

print("zero-order term")
print("<Phi|HN|Phi> = ",
      latex(wicks(HN, simplify_dummies=True, keep_only_fully_contracted=True)))
eqT2 = wicks(NO(Fd(i) * Fd(j) * F(b) * F(a)) * HN,
             simplify_dummies=True,
             keep_only_fully_contracted=True,
             simplify_kronecker_deltas=True)
P = PermutationOperator
eqT2 = simplify_index_permutations(eqT2, [P(a, b), P(i, j)])
print("<Phi|HN|Phi_ij^ab = ", latex(eqT2))
print()

C = Commutator
T1, T2 = get_CC_operators()
T = T2

print("[HN,T]-term")
comm1 = wicks(C(HN, T))
Exemplo n.º 21
0
print "Setting up hamiltonian"
p,q,r,s = symbols('pqrs',dummy=True)
f = AntiSymmetricTensor('f',(p,),(q,))
pr = NO((Fd(p)*F(q)))
v = AntiSymmetricTensor('v',(p,q),(r,s))
pqsr = NO(Fd(p)*Fd(q)*F(s)*F(r))

H=f*pr +Number(1,4)*v*pqsr

print "Calculating nested commutators"
C = Commutator

T1,T2 = get_CC_operators()
T = T1+ T2
print "comm1..."
comm1 = wicks(C(H,T),simplify_dummies=True, simplify_kronecker_deltas=True)

T1,T2 = get_CC_operators()
T = T1+ T2
print "comm2..."
comm2 = wicks(C(comm1,T),simplify_dummies=True, simplify_kronecker_deltas=True)

T1,T2 = get_CC_operators()
T = T1+ T2
print "comm3..."
comm3 = wicks(C(comm2,T),simplify_dummies=True, simplify_kronecker_deltas=True)

T1,T2 = get_CC_operators()
T = T1+ T2
print "comm4..."
comm4 = wicks(C(comm3,T),simplify_dummies=True, simplify_kronecker_deltas=True)
Exemplo n.º 22
0
def main():
    print()
    print("Calculates the Coupled-Cluster energy- and amplitude equations")
    print("See 'An Introduction to Coupled Cluster Theory' by")
    print("T. Daniel Crawford and Henry F. Schaefer III")
    print(
        "Reference to a Lecture Series: http://vergil.chemistry.gatech.edu/notes/sahan-cc-2010.pdf"
    )
    print()

    # setup hamiltonian
    p, q, r, s = symbols('p,q,r,s', cls=Dummy)
    f = AntiSymmetricTensor('f', (p, ), (q, ))
    pr = NO(Fd(p) * F(q))
    v = AntiSymmetricTensor('v', (p, q), (r, s))
    pqsr = NO(Fd(p) * Fd(q) * F(s) * F(r))

    H = f * pr + Rational(1, 4) * v * pqsr
    print("Using the hamiltonian:", latex(H))

    print("Calculating 4 nested commutators")
    C = Commutator

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 1...")
    comm1 = wicks(C(H, T))
    comm1 = evaluate_deltas(comm1)
    comm1 = substitute_dummies(comm1)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 2...")
    comm2 = wicks(C(comm1, T))
    comm2 = evaluate_deltas(comm2)
    comm2 = substitute_dummies(comm2)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 3...")
    comm3 = wicks(C(comm2, T))
    comm3 = evaluate_deltas(comm3)
    comm3 = substitute_dummies(comm3)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print("commutator 4...")
    comm4 = wicks(C(comm3, T))
    comm4 = evaluate_deltas(comm4)
    comm4 = substitute_dummies(comm4)

    print("construct Hausdorff expansion...")
    eq = H + comm1 + comm2 / 2 + comm3 / 6 + comm4 / 24
    eq = eq.expand()
    eq = evaluate_deltas(eq)
    eq = substitute_dummies(eq,
                            new_indices=True,
                            pretty_indices=pretty_dummies_dict)
    print("*********************")
    print()

    print("extracting CC equations from full Hbar")
    i, j, k, l = symbols('i,j,k,l', below_fermi=True)
    a, b, c, d = symbols('a,b,c,d', above_fermi=True)
    print()
    print("CC Energy:")
    print(
        latex(wicks(eq, simplify_dummies=True,
                    keep_only_fully_contracted=True)))

    # print("HERE")
    # print("HERE")
    # print("HERE")
    # print(pycode(wicks(eq, simplify_dummies=True,
    #     keep_only_fully_contracted=True)))
    # with open("cc_energy.py", "w") as f:
    # f.
    with open("ccsd.jl", "w") as f:
        eq_energy = wicks(eq,
                          simplify_dummies=True,
                          keep_only_fully_contracted=True)
        f.write(julia_code(eq_energy))

    print()
    print("CC T1:")
    eqT1 = wicks(NO(Fd(i) * F(a)) * eq,
                 simplify_kronecker_deltas=True,
                 keep_only_fully_contracted=True)
    eqT1 = substitute_dummies(eqT1)
    print(latex(eqT1))
    print()
    print("CC T2:")
    eqT2 = wicks(NO(Fd(i) * Fd(j) * F(b) * F(a)) * eq,
                 simplify_dummies=True,
                 keep_only_fully_contracted=True,
                 simplify_kronecker_deltas=True)
    # P = PermutationOperator
    # eqT2 = simplify_index_permutations(eqT2, [P(a, b), P(i, j)])
    print(latex(eqT2))
    print(latex(simplify(eqT2)))
Exemplo n.º 23
0
def main():
    print
    print "Calculates the Coupled-Cluster energy- and amplitude equations"
    print "See 'An Introduction to Coupled Cluster Theory' by"
    print "T. Daniel Crawford and Henry F. Schaefer III"
    print "http://www.ccc.uga.edu/lec_top/cc/html/review.html"
    print

    # setup hamiltonian
    p, q, r, s = symbols("pqrs", dummy=True)
    f = AntiSymmetricTensor("f", (p,), (q,))
    pr = NO((Fd(p) * F(q)))
    v = AntiSymmetricTensor("v", (p, q), (r, s))
    pqsr = NO(Fd(p) * Fd(q) * F(s) * F(r))

    H = f * pr

    # Uncomment the next line to use a 2-body hamiltonian:
    # H=f*pr + Number(1,4)*v*pqsr

    print "Using the hamiltonian:", latex(H)

    print "Calculating nested commutators"
    C = Commutator

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print "comm1..."
    comm1 = wicks(C(H, T), simplify_dummies=True, simplify_kronecker_deltas=True)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print "comm2..."
    comm2 = wicks(C(comm1, T), simplify_dummies=True, simplify_kronecker_deltas=True)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print "comm3..."
    comm3 = wicks(C(comm2, T), simplify_dummies=True, simplify_kronecker_deltas=True)

    T1, T2 = get_CC_operators()
    T = T1 + T2
    print "comm4..."
    comm4 = wicks(C(comm3, T), simplify_dummies=True, simplify_kronecker_deltas=True)

    print "construct Hausdoff expansion..."
    eq = H + comm1 + comm2 / 2 + comm3 / 6 + comm4 / 24
    eq = eq.expand()
    eq = evaluate_deltas(eq)
    eq = substitute_dummies(eq, new_indices=True, reverse_order=False, pretty_indices=pretty_dummies_dict)
    print "*********************"
    print

    print "extracting CC equations from full Hbar"
    i, j, k, l = symbols("ijkl", below_fermi=True)
    a, b, c, d = symbols("abcd", above_fermi=True)
    print
    print "CC Energy:"
    print latex(wicks(eq, simplify_dummies=True, keep_only_fully_contracted=True))
    print
    print "CC T1:"
    eqT1 = wicks(NO(Fd(i) * F(a)) * eq, simplify_kronecker_deltas=True, keep_only_fully_contracted=True)
    eqT1 = substitute_dummies(eqT1, reverse_order=False)
    print latex(eqT1)
    print
    print "CC T2:"
    eqT2 = wicks(
        NO(Fd(i) * Fd(j) * F(b) * F(a)) * eq,
        simplify_dummies=True,
        keep_only_fully_contracted=True,
        simplify_kronecker_deltas=True,
    )
    P = PermutationOperator
    eqT2 = simplify_index_permutations(eqT2, [P(a, b), P(i, j)])
    print latex(eqT2)
Exemplo n.º 24
0
def LVECTORS(L0, L1, L2, flavor):
    display(
        Markdown(
            rf""" Computing left sigma amplitudes for {flavor} (skipping summation for dummy variables)"""
        ))

    p, q, r, s = symbols('p,q,r,s', cls=Dummy)
    f = AntiSymmetricTensor('f', (p, ), (q, ))
    pr = NO((Fd(p) * F(q)))
    v = AntiSymmetricTensor('v', (p, q), (r, s))
    pqsr = NO(Fd(p) * Fd(q) * F(s) * F(r))
    ham = f * pr + Rational(1, 4) * v * pqsr

    cc = BCH.level(ham, "SD")
    E_cc = evaluate_deltas(wicks(cc, keep_only_fully_contracted=True))

    i, j, k = symbols('i,j,k', below_fermi=True)
    a, b, c = symbols('a,b,c', above_fermi=True)

    if flavor == "IP":
        sig11 = evaluate_deltas(
            wicks(L1 * (cc - E_cc) * F(i), keep_only_fully_contracted=True))
        index_rule = {'below': 'jklmno', 'above': 'abcdefg'}
        sig11 = substitute_dummies(sig11,
                                   new_indices=True,
                                   pretty_indices=index_rule)
    if flavor == "EA":
        sig11 = evaluate_deltas(
            wicks(L1 * (cc - E_cc) * Fd(a), keep_only_fully_contracted=True))
        index_rule = {'below': 'ijklmno', 'above': 'bcdefg'}
        sig11 = substitute_dummies(sig11,
                                   new_indices=True,
                                   pretty_indices=index_rule)
    if flavor == "DIP":
        PermutList = [PermutationOperator(i, j)]
        sig11 = evaluate_deltas(
            wicks(L1 * (cc - E_cc) * F(j) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'klmno', 'above': 'abcdefg'}
        sig11 = substitute_dummies(sig11,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig11 = simplify_index_permutations(sig11, PermutList)
    if flavor == "DEA":
        PermutList = [PermutationOperator(a, b)]
        sig11 = evaluate_deltas(
            wicks(L1 * (cc - E_cc) * Fd(a) * Fd(b),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'ijklmno', 'above': 'cdefg'}
        sig11 = substitute_dummies(sig11,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig11 = simplify_index_permutations(sig11, PermutList)

    sigma_11 = Symbol('(L_{1}(\overline{H}_{SS}-E_{cc}))')
    final_eq = Eq(sigma_11, sig11)
    display(final_eq)

    if flavor == "IP":
        PermutList = [PermutationOperator(i, j)]
        sig12 = evaluate_deltas(
            wicks((L2 * cc) * F(i), keep_only_fully_contracted=True))
        index_rule = {'below': 'jklmno', 'above': 'abcdefg'}
        sig12 = substitute_dummies(sig12,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig12 = simplify_index_permutations(sig12, PermutList)
    if flavor == "EA":
        PermutList = [PermutationOperator(a, b)]
        sig12 = evaluate_deltas(
            wicks((L2 * cc) * Fd(a), keep_only_fully_contracted=True))
        index_rule = {'below': 'ijklmno', 'above': 'bcdefg'}
        sig12 = substitute_dummies(sig12,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig12 = simplify_index_permutations(sig12, PermutList)
    if flavor == "DIP":
        PermutList = [
            PermutationOperator(i, j),
            PermutationOperator(j, k),
            PermutationOperator(i, k)
        ]
        sig12 = evaluate_deltas(
            wicks(L2 * cc * F(j) * F(i), keep_only_fully_contracted=True))
        index_rule = {'below': 'klmno', 'above': 'abcdefg'}
        sig12 = substitute_dummies(sig12,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig12 = simplify_index_permutations(sig12, PermutList)
    if flavor == "DEA":
        PermutList = [
            PermutationOperator(a, b),
            PermutationOperator(b, c),
            PermutationOperator(a, c)
        ]
        sig12 = evaluate_deltas(
            wicks((L2 * cc) * Fd(a) * Fd(b), keep_only_fully_contracted=True))
        index_rule = {'below': 'ijklmno', 'above': 'cdefg'}
        sig12 = substitute_dummies(sig12,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig12 = simplify_index_permutations(sig12, PermutList)

    sigma_12 = Symbol('(L_{2}\overline{H}_{DS})')
    final_eq = Eq(sigma_12, sig12)
    display(final_eq)

    if flavor == "IP":
        sig21 = evaluate_deltas(
            wicks((L1 * cc) * Fd(a) * F(j) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'klmno', 'above': 'bcdefgh'}
        sig21 = substitute_dummies(sig21,
                                   new_indices=True,
                                   pretty_indices=index_rule)
    if flavor == "EA":
        sig21 = evaluate_deltas(
            wicks((L1 * cc) * Fd(a) * Fd(b) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'jklmno', 'above': 'cdefgh'}
        sig21 = substitute_dummies(sig21,
                                   new_indices=True,
                                   pretty_indices=index_rule)
    if flavor == "DIP":
        PermutList = [PermutationOperator(i, j)]
        sig21 = evaluate_deltas(
            wicks(L1 * cc * Fd(a) * F(k) * F(j) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'lmno', 'above': 'bcdefgh'}
        sig21 = substitute_dummies(sig21,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig21 = simplify_index_permutations(sig21, PermutList)
    if flavor == "DEA":
        PermutList = [PermutationOperator(a, b)]
        sig21 = evaluate_deltas(
            wicks((L1 * cc) * Fd(a) * Fd(b) * Fd(c) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'jklmno', 'above': 'defgh'}
        sig21 = substitute_dummies(sig21,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig21 = simplify_index_permutations(sig21, PermutList)

    sigma_21 = Symbol('(L_{1}\overline{H}_{SD})')
    final_eq = Eq(sigma_21, sig21)
    display(final_eq)

    if flavor == "IP":
        PermutList = [PermutationOperator(i, j)]
        sig22 = evaluate_deltas(
            wicks(L2 * (cc - E_cc) * Fd(a) * F(j) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'klmno', 'above': 'bcdefgh'}
        sig22 = substitute_dummies(sig22,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig22 = simplify_index_permutations(sig22, PermutList)
    if flavor == "EA":
        PermutList = [PermutationOperator(a, b)]
        sig22 = evaluate_deltas(
            wicks(L2 * (cc - E_cc) * Fd(a) * Fd(b) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'jklmno', 'above': 'cdefgh'}
        sig22 = substitute_dummies(sig22,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig22 = simplify_index_permutations(sig22, PermutList)
    if flavor == "DIP":
        PermutList = [
            PermutationOperator(i, j),
            PermutationOperator(j, k),
            PermutationOperator(i, k)
        ]
        sig22 = evaluate_deltas(
            wicks(L2 * (cc - E_cc) * Fd(a) * F(k) * F(j) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'lmno', 'above': 'bcdefgh'}
        sig22 = substitute_dummies(sig22,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig22 = simplify_index_permutations(sig22, PermutList)
    if flavor == "DEA":
        PermutList = [
            PermutationOperator(a, b),
            PermutationOperator(b, c),
            PermutationOperator(a, c)
        ]
        sig22 = evaluate_deltas(
            wicks(L2 * (cc - E_cc) * Fd(a) * Fd(b) * Fd(c) * F(i),
                  keep_only_fully_contracted=True))
        index_rule = {'below': 'jklmno', 'above': 'defgh'}
        sig22 = substitute_dummies(sig22,
                                   new_indices=True,
                                   pretty_indices=index_rule)
        sig22 = simplify_index_permutations(sig22, PermutList)

    sigma_22 = Symbol('(L_{2}(\overline{H}_{DD}-E_{cc}))')
    final_eq = Eq(sigma_22, sig22)
    display(final_eq)
def get_energy_equation(equation_h, equation_u):
    energy = wicks(equation_h + equation_u, **wicks_kwargs)
    energy = substitute_dummies(energy, **sub_kwargs)

    return energy
Exemplo n.º 26
0
from sympy import symbols, latex, WildFunction, collect, Rational, simplify
from sympy.physics.secondquant import F, Fd, wicks, AntiSymmetricTensor, substitute_dummies, NO, evaluate deltas

"""
Define Hamiltonian and the second-quantized representation of a three-body Slater determinant.
"""

# Define Hamiltonian
p, q, r, s = symbols("p q r s", dummy=True)
f = AntiSymmetricTensor("f", (p,), (q,))
pr = Fd(p) * F(q)
v = AntiSymmetricTensor("v", (p, q), (r, s))
pqsr = Fd(p) * Fd(q) * F(s) * F(r)
Hamiltonian = f * pr + Rational(1) / Rational(4) * v * pqsr
a, b, c, d, e, f = symbols("a, b, c, d, e, f", above_fermi=True)

# Create teh representatoin
expression = wicks(F(c) * F(b) * F(a) * Hamiltonian * Fd(d) * Fd(e) * Fd(f), keep_only_fully_contracted=True, simplify_kronecker_deltas=True)
expression = evaluate_deltas(expression)
expression = simplify(expression)
print(latex(expression))
Exemplo n.º 27
0
def TPDM(L, R, flavor):

    display(
        Markdown(
            rf""" Computing TPDM for {flavor} (skipping summation for dummy variables)"""
        ))

    i, j, k, l = symbols('i,j,k,l', below_fermi=True)
    a, b, c, d = symbols('a,b,c,d', above_fermi=True)

    oooo = Fd(i) * Fd(j) * F(l) * F(k)
    cc = BCH.level(oooo, "SD")
    g_oooo = evaluate_deltas(wicks(L * cc * R,
                                   keep_only_fully_contracted=True))
    PermutList = [PermutationOperator(i,j),PermutationOperator(i,k), \
               PermutationOperator(i,l),PermutationOperator(j,k), \
               PermutationOperator(j,l),PermutationOperator(k,l)]
    g_oooo = simplify_index_permutations(g_oooo, PermutList)
    index_rule = {'below': 'mnop', 'above': 'abcde'}
    g_oooo = substitute_dummies(g_oooo,
                                new_indices=True,
                                pretty_indices=index_rule)
    gamma = Symbol('\gamma_{ijkl}')
    final_eq = Eq(gamma, g_oooo)
    display(final_eq)

    ooov = Fd(i) * Fd(j) * F(a) * F(k)
    cc = BCH.level(ooov, "SD")
    g_ooov = evaluate_deltas(wicks(L * cc * R,
                                   keep_only_fully_contracted=True))
    PermutList = [PermutationOperator(i,j),PermutationOperator(i,k), \
               PermutationOperator(j,k)]
    g_ooov = simplify_index_permutations(g_ooov, PermutList)
    index_rule = {'below': 'lmnop', 'above': 'bcdef'}
    g_ooov = substitute_dummies(g_ooov,
                                new_indices=True,
                                pretty_indices=index_rule)
    gamma = Symbol('\gamma_{ijka}')
    final_eq = Eq(gamma, g_oo)
    display(final_eq)

    ooov = Fd(i) * Fd(a) * F(k) * F(j)
    cc = BCH.level(ooov, "SD")
    g_ovoo = evaluate_deltas(wicks(L * cc * R,
                                   keep_only_fully_contracted=True))
    PermutList = [PermutationOperator(i,j),PermutationOperator(i,k), \
               PermutationOperator(j,k)]
    g_ovoo = simplify_index_permutations(g_ovoo, PermutList)
    index_rule = {'below': 'lmnop', 'above': 'bcdef'}
    g_ovoo = substitute_dummies(g_ovoo,
                                new_indices=True,
                                pretty_indices=index_rule)
    gamma = Symbol('\gamma_{iajk}')
    final_eq = Eq(gamma, g_ovoo)
    display(final_eq)

    ovov = Fd(i) * Fd(a) * F(b) * F(j)
    cc = BCH.level(ovov, "SD")
    g_ovov = evaluate_deltas(wicks(L * cc * R,
                                   keep_only_fully_contracted=True))
    PermutList = [PermutationOperator(i, j), PermutationOperator(a, b)]
    g_ovov = simplify_index_permutations(g_ovov, PermutList)
    index_rule = {'below': 'klmno', 'above': 'cdef'}
    g_ovov = substitute_dummies(g_ovov,
                                new_indices=True,
                                pretty_indices=index_rule)
    gamma = Symbol('\gamma_{iajb}')
    final_eq = Eq(gamma, g_ovov)
    display(final_eq)

    ovvv = Fd(i) * Fd(a) * F(c) * F(b)
    cc = BCH.level(ovvv, "SD")
    g_ovvv = evaluate_deltas(wicks(L * cc * R,
                                   keep_only_fully_contracted=True))
    PermutList = [PermutationOperator(a,b),PermutationOperator(a,c), \
               PermutationOperator(b,c)]
    g_ovvv = simplify_index_permutations(g_ovvv, PermutList)
    index_rule = {'below': 'jklmn', 'above': 'defg'}
    g_ovvv = substitute_dummies(g_ovvv,
                                new_indices=True,
                                pretty_indices=index_rule)
    gamma = Symbol('\gamma_{iabc}')
    final_eq = Eq(gamma, g_ovvv)
    display(final_eq)

    oovv = Fd(i) * Fd(j) * F(b) * F(a)
    cc = BCH.level(oovv, "SD")
    g_oovv = evaluate_deltas(wicks(L * cc * R,
                                   keep_only_fully_contracted=True))
    PermutList = [PermutationOperator(i, j), PermutationOperator(a, b)]
    g_oovv = simplify_index_permutations(g_oovv, PermutList)
    index_rule = {'below': 'klmn', 'above': 'cdefg'}
    g_oovv = substitute_dummies(g_oovv,
                                new_indices=True,
                                pretty_indices=index_rule)
    gamma = Symbol('\gamma_{ijab}')
    final_eq = Eq(gamma, g_oovv)
    display(final_eq)
Exemplo n.º 28
0
def eval_equation(eq):
    eq = wicks(eq, **wicks_kwargs)
    eq = evaluate_deltas(eq.expand())
    eq = substitute_dummies(eq, **sub_kwargs)

    return eq