def get_bc(self,matrix=None,is_vector=False):
'''Calculates Barycenter for scalar field
'''
# Initialize variable
self.bc = numpy.zeros(3)
# Calculation of barycenter
from orbkit import grid
if not is_vector:
grid.grid2vector()
xyz = grid.tolist()
for i in range(3):
self.bc[i] = (matrix.reshape((-1,))*xyz[i]).sum()
self.bc /= matrix.sum()
if not is_vector:
grid.vector2grid(*grid.N_)
return self.bc
display.display(grid.get_grid())
# Choose the molecular orbitals to be calculated
selected_MO = ['1.1_a', '1.5_a']
qc.mo_spec = read.mo_select(qc.mo_spec, selected_MO, strict=True)['mo_spec']
# Calculate molecular orbitals
mo_list = core.rho_compute(qc,
calc_mo=True,
slice_length=slice_length,
drv=None,
numproc=numproc)
# Calculate analytic derivatives of molecular orbitals
mo_list_drv = core.rho_compute(qc,
calc_mo=True,
slice_length=slice_length,
drv='xyz',
numproc=numproc)
# Calculate Transition Electronic Flux Densities (time independent)
# Calculate the STEFD [in units of (i E_h/(hbar a_0^2))]
j_stefd = -0.5 * (mo_list[numpy.newaxis, 0] * mo_list_drv[:, 1] -
mo_list[numpy.newaxis, 1] * mo_list_drv[:, 0])
Z, Y, X = output.meshgrid2(*grid.tolist()[::-1])
mlab.quiver3d(X, Y, Z, *j_stefd)
mlab.show()