Example #1
0
class LJCutTest(unittest.TestCase):
    def setUp(self):
        self.natoms = 10
        self.coords = np.random.uniform(-1,1.,3*self.natoms) * self.natoms**(-1./3)
        self.pot = LJCut()
        self.E = self.pot.getEnergy(self.coords)
        self.Egrad, self.grad = self.pot.getEnergyGradient(self.coords)
        
        import itertools
        self.ilist = [] #np.zeros([self.natoms*(self.natoms-1)/2, 2])
        k = 0
        for i in range(self.natoms):
            for j in range(i):
                k += 1
                self.ilist.append( [i,j] )
        self.ilist = np.array(self.ilist) 
        #print self.ilist
    
    def test_grad_e(self):
        self.assertAlmostEqual(self.E, self.Egrad, 7)
    def test_lists_e(self):
        e = self.pot.getEnergyList(self.coords, self.ilist)
        self.assertAlmostEqual(self.E, e, 7)
    def test_lists_eg(self):
        e, g = self.pot.getEnergyGradientList(self.coords, self.ilist)
        self.assertAlmostEqual(self.E, e, 7)
        gdiffmax = np.max(np.abs( g-self.grad )) / np.max(np.abs(self.grad))
        self.assertLess(gdiffmax, 1e-7)
Example #2
0
class LJCutTest(unittest.TestCase):
    def setUp(self):
        self.natoms = 10
        self.coords = np.random.uniform(
            -1, 1., 3 * self.natoms) * self.natoms**(-1. / 3)
        self.pot = LJCut()
        self.E = self.pot.getEnergy(self.coords)
        self.Egrad, self.grad = self.pot.getEnergyGradient(self.coords)

        self.ilist = []  # np.zeros([self.natoms*(self.natoms-1)/2, 2])
        k = 0
        for i in range(self.natoms):
            for j in range(i):
                k += 1
                self.ilist.append([i, j])
        self.ilist = np.array(self.ilist)
        # print self.ilist

    def test_grad_e(self):
        self.assertAlmostEqual(self.E, self.Egrad, 7)

    def test_lists_e(self):
        e = self.pot.getEnergyList(self.coords, self.ilist)
        self.assertAlmostEqual(self.E, e, 7)

    def test_lists_eg(self):
        e, g = self.pot.getEnergyGradientList(self.coords, self.ilist)
        self.assertAlmostEqual(self.E, e, 7)
        gdiffmax = np.max(np.abs(g - self.grad)) / np.max(np.abs(self.grad))
        self.assertLess(gdiffmax, 1e-7)
Example #3
0
    def setUp(self):
        self.natoms = 10
        self.coords = np.random.uniform(
            -1, 1., 3 * self.natoms) * self.natoms**(-1. / 3)
        self.pot = LJCut()
        self.E = self.pot.getEnergy(self.coords)
        self.Egrad, self.grad = self.pot.getEnergyGradient(self.coords)

        self.ilist = []  # np.zeros([self.natoms*(self.natoms-1)/2, 2])
        k = 0
        for i in range(self.natoms):
            for j in range(i):
                k += 1
                self.ilist.append([i, j])
        self.ilist = np.array(self.ilist)
Example #4
0
    def setUp(self):
        self.natoms = 10
        self.coords = np.random.uniform(-1, 1., 3 * self.natoms) * self.natoms ** (-1. / 3)
        self.pot = LJCut()
        self.E = self.pot.getEnergy(self.coords)
        self.Egrad, self.grad = self.pot.getEnergyGradient(self.coords)

        self.ilist = []  # np.zeros([self.natoms*(self.natoms-1)/2, 2])
        k = 0
        for i in range(self.natoms):
            for j in range(i):
                k += 1
                self.ilist.append([i, j])
        self.ilist = np.array(self.ilist)
Example #5
0
def makeBLJNeighborListPotFreeze(natoms,
                                 frozenlist,
                                 ntypeA=None,
                                 rcut=2.5,
                                 boxl=None):
    """
    create the potential object for the kob andersen binary lennard jones with frozeen particles
    
    Parameters
    ----------
    natoms :
        number of atoms in the system
    frozenlist : 
        list of frozen atoms
    ntypeA : 
        number of atoms of type A.  It is assumed that they have indices in [0,ntypeA]
    rcut : 
        the cutoff for the lj potential in units of sigA
    boxl : 
        the box length for periodic box.  None for no periodic boundary conditions
    """
    print "making BLJ neighborlist potential", natoms, ntypeA, rcut, boxl
    if ntypeA is None:
        ntypeA = int(natoms * 0.8)
    Alist = range(ntypeA)
    Blist = range(ntypeA, natoms)

    frozenA = np.array([i for i in Alist if i in frozenlist])
    mobileA = np.array([i for i in Alist if i not in frozenlist])
    frozenB = np.array([i for i in Blist if i in frozenlist])
    mobileB = np.array([i for i in Blist if i not in frozenlist])

    blj = ljpshift.LJpshift(natoms, ntypeA, rcut=rcut)

    ljAA = LJCut(eps=blj.AA.eps,
                 sig=blj.AA.sig,
                 rcut=rcut * blj.AA.sig,
                 boxl=boxl)
    ljBB = LJCut(eps=blj.BB.eps,
                 sig=blj.BB.sig,
                 rcut=rcut * blj.BB.sig,
                 boxl=boxl)
    ljAB = LJCut(eps=blj.AB.eps,
                 sig=blj.AB.sig,
                 rcut=rcut * blj.AB.sig,
                 boxl=boxl)

    # ten lists in total
    # nlAA_ff
    # nlAA_mm
    # nlAA_mf
    # nlBB_ff
    # nlBB_mm
    # nlBB_mf
    # nlAB_ff
    # nlAB_mm
    # nlAB_mf
    # nlAB_fm

    nlAA_ff = NeighborListSubsetBuild(natoms, rcut, frozenA, boxl=boxl)
    nlAA_mm = NeighborListSubsetBuild(natoms, rcut, mobileA, boxl=boxl)
    nlAA_mf = NeighborListSubsetBuild(natoms,
                                      rcut,
                                      mobileA,
                                      Blist=frozenA,
                                      boxl=boxl)

    nlBB_ff = NeighborListSubsetBuild(natoms, rcut, frozenB, boxl=boxl)
    nlBB_mm = NeighborListSubsetBuild(natoms, rcut, mobileB, boxl=boxl)
    nlBB_mf = NeighborListSubsetBuild(natoms,
                                      rcut,
                                      mobileB,
                                      Blist=frozenB,
                                      boxl=boxl)

    nlAB_ff = NeighborListSubsetBuild(natoms,
                                      rcut,
                                      frozenA,
                                      Blist=frozenB,
                                      boxl=boxl)
    nlAB_mm = NeighborListSubsetBuild(natoms,
                                      rcut,
                                      mobileA,
                                      Blist=mobileB,
                                      boxl=boxl)
    nlAB_mf = NeighborListSubsetBuild(natoms,
                                      rcut,
                                      mobileA,
                                      Blist=frozenB,
                                      boxl=boxl)
    nlAB_fm = NeighborListSubsetBuild(natoms,
                                      rcut,
                                      mobileB,
                                      Blist=frozenA,
                                      boxl=boxl)

    potlist_frozen = [
        NeighborListPotentialBuild(nlAA_ff, ljAA),
        NeighborListPotentialBuild(nlBB_ff, ljBB),
        NeighborListPotentialBuild(nlAB_ff, ljAB)
    ]
    potlist_mobile = [
        NeighborListPotentialBuild(nlAA_mm, ljAA),
        NeighborListPotentialBuild(nlAA_mf, ljAA),
        NeighborListPotentialBuild(nlBB_mm, ljBB),
        NeighborListPotentialBuild(nlBB_mf, ljBB),
        NeighborListPotentialBuild(nlAB_mm, ljAB),
        NeighborListPotentialBuild(nlAB_mf, ljAB),
        NeighborListPotentialBuild(nlAB_fm, ljAB),
    ]

    # wrap the mobile potentials so the check for whether coords needs to be updated
    # can be done all at once
    mobile_pot = NeighborListPotentialMulti(potlist_mobile,
                                            natoms,
                                            rcut,
                                            boxl=boxl)

    # wrap the mobile and frozen potentials together
    mcpot = MultiComponentSystemFreeze([mobile_pot], potlist_frozen)

    # finally, wrap it once more in a class that will zero the gradients of the frozen atoms
    frozenpot = FreezePot(mcpot, frozenlist, natoms)
    return frozenpot