mirror of https://github.com/QMCPACK/qmcpack.git
32 lines
757 B
Python
Executable File
32 lines
757 B
Python
Executable File
#! /usr/bin/env python3
|
|
|
|
from math import cos, sin, pi, acos
|
|
import numpy
|
|
from pyscf import gto, scf
|
|
|
|
# Bond angle HCH
|
|
alpha = acos(-1.0/3.0)
|
|
# Rotation angle about z.
|
|
beta = 2*pi / 3.0
|
|
c = cos(beta)
|
|
s = sin(beta)
|
|
# Rotation matrix about z axis.
|
|
R = numpy.array([[c, -s, 0], [s, c, 0], [0, 0, 1]])
|
|
# C-H bond length in angstrom
|
|
rch = 1.1085
|
|
# Rotation matrix for geometry
|
|
C = numpy.array([0, 0, 0])
|
|
H1 = numpy.array([0, 0, rch])
|
|
# Arbitrary position of first HCH molecule
|
|
H2 = numpy.array([rch*cos(alpha-pi/2.), 0, -rch*sin(alpha-pi/2.)])
|
|
H3 = R.dot(H2)
|
|
H4 = R.dot(H3)
|
|
|
|
mol = gto.M(atom=[['C', C], ['H', H1], ['H', H2], ['H', H3], ['H', H4]],
|
|
basis='sto-3g',
|
|
unit='Angstrom')
|
|
|
|
mf = scf.RHF(mol)
|
|
mf.chkfile = 'scf.chk'
|
|
ehf = mf.scf()
|