Ejemplo n.º 1
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)
Ejemplo n.º 2
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)
Ejemplo n.º 3
0
def test_contraction():
    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")
    assert contraction(Fd(i), F(j)) == KroneckerDelta(i, j)
    assert contraction(F(a), Fd(b)) == KroneckerDelta(a, b)
    assert contraction(F(a), Fd(i)) == 0
    assert contraction(Fd(a), F(i)) == 0
    assert contraction(F(i), Fd(a)) == 0
    assert contraction(Fd(i), F(a)) == 0
    assert contraction(Fd(i), F(p)) == KroneckerDelta(i, p)
    restr = evaluate_deltas(contraction(Fd(p), F(q)))
    assert restr.is_only_below_fermi
    restr = evaluate_deltas(contraction(F(p), Fd(q)))
    assert restr.is_only_above_fermi
Ejemplo n.º 4
0
def test_contraction():
    i,j,k,l = symbols('ijkl',below_fermi=True)
    a,b,c,d = symbols('abcd',above_fermi=True)
    p,q,r,s = symbols('pqrs')
    assert contraction(Fd(i),F(j)) == KroneckerDelta(i,j)
    assert contraction(F(a),Fd(b)) == KroneckerDelta(a,b)
    assert contraction(F(a),Fd(i)) == 0
    assert contraction(Fd(a),F(i)) == 0
    assert contraction(F(i),Fd(a)) == 0
    assert contraction(Fd(i),F(a)) == 0
    assert contraction(Fd(i),F(p)) == KroneckerDelta(p,i)
    restr = evaluate_deltas(contraction(Fd(p),F(q)))
    assert restr.is_only_below_fermi
    restr = evaluate_deltas(contraction(F(p),Fd(q)))
    assert restr.is_only_above_fermi
Ejemplo n.º 5
0
def test_contraction():
    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')
    assert contraction(Fd(i), F(j)) == KroneckerDelta(i, j)
    assert contraction(F(a), Fd(b)) == KroneckerDelta(a, b)
    assert contraction(F(a), Fd(i)) == 0
    assert contraction(Fd(a), F(i)) == 0
    assert contraction(F(i), Fd(a)) == 0
    assert contraction(Fd(i), F(a)) == 0
    assert contraction(Fd(i), F(p)) == KroneckerDelta(i, p)
    restr = evaluate_deltas(contraction(Fd(p), F(q)))
    assert restr.is_only_below_fermi
    restr = evaluate_deltas(contraction(F(p), Fd(q)))
    assert restr.is_only_above_fermi
Ejemplo n.º 6
0
def test_contraction():
    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")
    assert contraction(Fd(i), F(j)) == KroneckerDelta(i, j)
    assert contraction(F(a), Fd(b)) == KroneckerDelta(a, b)
    assert contraction(F(a), Fd(i)) == 0
    assert contraction(Fd(a), F(i)) == 0
    assert contraction(F(i), Fd(a)) == 0
    assert contraction(Fd(i), F(a)) == 0
    assert contraction(Fd(i), F(p)) == KroneckerDelta(i, p)
    restr = evaluate_deltas(contraction(Fd(p), F(q)))
    assert restr.is_only_below_fermi
    restr = evaluate_deltas(contraction(F(p), Fd(q)))
    assert restr.is_only_above_fermi
    raises(ContractionAppliesOnlyToFermions, lambda: contraction(B(a), Fd(b)))
Ejemplo n.º 7
0
def test_contraction():
    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')
    assert contraction(Fd(i), F(j)) == KroneckerDelta(i, j)
    assert contraction(F(a), Fd(b)) == KroneckerDelta(a, b)
    assert contraction(F(a), Fd(i)) == 0
    assert contraction(Fd(a), F(i)) == 0
    assert contraction(F(i), Fd(a)) == 0
    assert contraction(Fd(i), F(a)) == 0
    assert contraction(Fd(i), F(p)) == KroneckerDelta(i, p)
    restr = evaluate_deltas(contraction(Fd(p), F(q)))
    assert restr.is_only_below_fermi
    restr = evaluate_deltas(contraction(F(p), Fd(q)))
    assert restr.is_only_above_fermi
    raises(ContractionAppliesOnlyToFermions, lambda: contraction(B(a), Fd(b)))
Ejemplo n.º 8
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
Ejemplo n.º 11
0
def test_evaluate_deltas():
    i, j, k = symbols("i,j,k")

    r = KroneckerDelta(i, j) * KroneckerDelta(j, k)
    assert evaluate_deltas(r) == KroneckerDelta(i, k)

    r = KroneckerDelta(i, 0) * KroneckerDelta(j, k)
    assert evaluate_deltas(r) == KroneckerDelta(i, 0) * KroneckerDelta(j, k)

    r = KroneckerDelta(1, j) * KroneckerDelta(j, k)
    assert evaluate_deltas(r) == KroneckerDelta(1, k)

    r = KroneckerDelta(j, 2) * KroneckerDelta(k, j)
    assert evaluate_deltas(r) == KroneckerDelta(2, k)

    r = KroneckerDelta(i, 0) * KroneckerDelta(i, j) * KroneckerDelta(j, 1)
    assert evaluate_deltas(r) == 0

    r = (
        KroneckerDelta(0, i)
        * KroneckerDelta(0, j)
        * KroneckerDelta(1, j)
        * KroneckerDelta(1, j)
    )
    assert evaluate_deltas(r) == 0
Ejemplo n.º 12
0
def test_evaluate_deltas():
    i, j, k = symbols('i,j,k')

    r = KroneckerDelta(i, j) * KroneckerDelta(j, k)
    assert evaluate_deltas(r) == KroneckerDelta(i, k)

    r = KroneckerDelta(i, 0) * KroneckerDelta(j, k)
    assert evaluate_deltas(r) == KroneckerDelta(i, 0) * KroneckerDelta(j, k)

    r = KroneckerDelta(1, j) * KroneckerDelta(j, k)
    assert evaluate_deltas(r) == KroneckerDelta(1, k)

    r = KroneckerDelta(j, 2) * KroneckerDelta(k, j)
    assert evaluate_deltas(r) == KroneckerDelta(2, k)

    r = KroneckerDelta(i, 0) * KroneckerDelta(i, j) * KroneckerDelta(j, 1)
    assert evaluate_deltas(r) == 0

    r = (KroneckerDelta(0, i) * KroneckerDelta(0, j)
         * KroneckerDelta(1, j) * KroneckerDelta(1, j))
    assert evaluate_deltas(r) == 0
Ejemplo n.º 13
0
#Link to Second quant documentation: https://docs.sympy.org/latest/modules/physics/secondquant.html

pretty_dummies_dict = {
    'above': 'abcdefgh',
    'below': 'ijklmno',
    'general': 'pqrstu'
}

p, q, r, s = symbols('p,q,r,s', cls=Dummy)

#Setup creation and annihilation operators
ap_dagger = Fd(p)
aq = F(q)
#Perform a contraction
contr = evaluate_deltas(contraction(ap_dagger, aq))
print("Example outputs")
print()
print("contraction(a_p^\dagger a_q): ", latex(contr))
print()

#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
Ejemplo n.º 14
0
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))
comm1 = evaluate_deltas(comm1)
comm1 = substitute_dummies(comm1,
                           new_indices=True,
                           pretty_indices=pretty_dummies_dict)
print(
    "<Phi|[HN,T]|Phi> = ",
    latex(wicks(comm1, simplify_dummies=True,
                keep_only_fully_contracted=True)))
eqT2 = wicks(NO(Fd(i) * Fd(j) * F(b) * F(a)) * comm1,
             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,T]|Phi_ij^ab = ", latex(eqT2))
print()
Ejemplo n.º 15
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))
Ejemplo n.º 16
0
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)
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)
Ejemplo n.º 17
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)
Ejemplo 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(
        "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)))
Ejemplo n.º 19
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)
Ejemplo n.º 20
0
T = sum(get_ccsd_t_operators())
T_2 = sum(get_ccsd_t_operators())
T_t = sum(get_ccsd_t_operators(ast_symb="t(t)"))
T_t_2 = sum(get_ccsd_t_operators(ast_symb="t(t)"))
L = sum(get_ccsd_lambda_operators())
L_t = sum(get_ccsd_lambda_operators(ast_symb="l(t)"))

tilde_t_eq = Rational(1, 1)
tilde_t_eq += eval_equation(-L_t * T_t)
tilde_t_eq += eval_equation(L_t * T)
tilde_t_eq += eval_equation(-L_t * T_t * T)
tilde_t_eq += eval_equation(Rational(1, 2) * L_t * T_t * T_t_2)
tilde_t_eq += eval_equation(Rational(1, 2) * L_t * T * T_2)

tilde_t_eq = tilde_t_eq.expand()
tilde_t_eq = evaluate_deltas(tilde_t_eq)
tilde_t_eq = substitute_dummies(tilde_t_eq, **sub_kwargs)

tilde_eq = Rational(1, 1)
tilde_eq += eval_equation(-L * T)
tilde_eq += eval_equation(L * T_t)
tilde_eq += eval_equation(-L * T * T_t)
tilde_eq += eval_equation(Rational(1, 2) * L * T * T_2)
tilde_eq += eval_equation(Rational(1, 2) * L * T_t * T_t_2)

tilde_eq = tilde_eq.expand()
tilde_eq = evaluate_deltas(tilde_eq)
tilde_eq = substitute_dummies(tilde_eq, **sub_kwargs)

print(latex(tilde_t_eq))
print(latex(tilde_eq))
Ejemplo n.º 21
0
        (
            "rho^{a}_{i} = ",
            (
                symbols("p", below_fermi=True, cls=Dummy),
                symbols("q", above_fermi=True, cls=Dummy),
            ),
        ),
        ("rho^{j}_{i} = ", symbols("p, q", below_fermi=True, cls=Dummy)),
    ]

    for label, (p, q) in symbol_list:
        c_pq = Fd(p) * F(q)

        T = sum(get_ccsd_t_operators())
        L = sum(get_ccsd_lambda_operators())

        # Only keep non-zero terms
        rho_eq = eval_equation(c_pq)
        rho_eq += eval_equation(Commutator(c_pq, T))
        rho_eq += eval_equation(L * c_pq)
        comm = Commutator(c_pq, T)
        rho_eq += eval_equation(L * comm)
        comm = Commutator(comm, sum(get_ccsd_t_operators()))
        rho_eq += Rational(1, 2) * eval_equation(L * comm)

        rho = rho_eq.expand()
        rho = evaluate_deltas(rho)
        rho = substitute_dummies(rho, **sub_kwargs)

        print(label + latex(rho))
Ejemplo n.º 22
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)
Ejemplo n.º 23
0
def eval_equation(eq):
    eq = wicks(eq, **wicks_kwargs)
    eq = evaluate_deltas(eq.expand())
    eq = substitute_dummies(eq, **sub_kwargs)

    return eq