Source code for pyscf.mcscf.umc2step

#!/usr/bin/env python
# Copyright 2014-2020 The PySCF Developers. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Author: Qiming Sun <osirpt.sun@gmail.com>
#

'''
UCASSCF (CASSCF without spin-degeneracy between alpha and beta orbitals)
2-step optimization algorithm
'''

import time
import numpy
import copy
import pyscf.lib.logger as logger

[docs]def kernel(casscf, mo_coeff, tol=1e-7, conv_tol_grad=None, ci0=None, callback=None, verbose=None, dump_chk=True): if verbose is None: verbose = casscf.verbose log = logger.Logger(casscf.stdout, verbose) cput0 = (time.clock(), time.time()) log.debug('Start 2-step CASSCF') mo = mo_coeff nmo = mo[0].shape[1] ncore = casscf.ncore eris = casscf.ao2mo(mo) e_tot, e_cas, fcivec = casscf.casci(mo, ci0, eris, log, locals()) if casscf.ncas == nmo and not casscf.internal_rotation: return True, e_tot, e_cas, fcivec, mo if conv_tol_grad is None: conv_tol_grad = numpy.sqrt(tol) logger.info(casscf, 'Set conv_tol_grad to %g', conv_tol_grad) conv_tol_ddm = conv_tol_grad * 3 conv = False de, elast = e_tot, e_tot totmicro = totinner = 0 casdm1 = (0,0) r0 = None t2m = t1m = log.timer('Initializing 2-step CASSCF', *cput0) imacro = 0 while not conv and imacro < casscf.max_cycle_macro: imacro += 1 njk = 0 t3m = t2m casdm1_old = casdm1 casdm1, casdm2 = casscf.fcisolver.make_rdm12s(fcivec, casscf.ncas, casscf.nelecas) norm_ddm =(numpy.linalg.norm(casdm1[0] - casdm1_old[0]) + numpy.linalg.norm(casdm1[1] - casdm1_old[1])) t3m = log.timer('update CAS DM', *t3m) max_cycle_micro = 1 # casscf.micro_cycle_scheduler(locals()) max_stepsize = casscf.max_stepsize_scheduler(locals()) for imicro in range(max_cycle_micro): rota = casscf.rotate_orb_cc(mo, lambda:fcivec, lambda:casdm1, lambda:casdm2, eris, r0, conv_tol_grad*.3, max_stepsize, log) u, g_orb, njk1, r0 = next(rota) rota.close() njk += njk1 norm_t = numpy.linalg.norm(u-numpy.eye(nmo)) norm_gorb = numpy.linalg.norm(g_orb) if imicro == 0: norm_gorb0 = norm_gorb t3m = log.timer('orbital rotation', *t3m) eris = None u = copy.copy(u) g_orb = copy.copy(g_orb) mo = casscf.rotate_mo(mo, u, log) eris = casscf.ao2mo(mo) t3m = log.timer('update eri', *t3m) log.debug('micro %d |u-1|=%5.3g |g[o]|=%5.3g |dm1|=%5.3g', imicro, norm_t, norm_gorb, norm_ddm) if callable(callback): callback(locals()) t2m = log.timer('micro iter %d'%imicro, *t2m) if norm_t < 1e-4 or norm_gorb < conv_tol_grad*.5: break totinner += njk totmicro += imicro+1 e_tot, e_cas, fcivec = casscf.casci(mo, fcivec, eris, log, locals()) log.timer('CASCI solver', *t3m) t2m = t1m = log.timer('macro iter %d'%imacro, *t1m) de, elast = e_tot - elast, e_tot if (abs(de) < tol and norm_gorb < conv_tol_grad and norm_ddm < conv_tol_ddm): conv = True if dump_chk: casscf.dump_chk(locals()) if callable(callback): callback(locals()) if conv: log.info('2-step CASSCF converged in %d macro (%d JK %d micro) steps', imacro+1, totinner, totmicro) else: log.info('2-step CASSCF not converged, %d macro (%d JK %d micro) steps', imacro+1, totinner, totmicro) log.timer('2-step CASSCF', *cput0) return conv, e_tot, e_cas, fcivec, mo
if __name__ == '__main__': from pyscf import gto from pyscf import scf from pyscf.mcscf import addons from pyscf.mcscf import umc1step mol = gto.Mole() mol.verbose = 0 mol.output = None#"out_h2o" mol.atom = [ ['H', ( 1.,-1. , 0. )], ['H', ( 0.,-1. ,-1. )], ['H', ( 1.,-0.5 ,-1. )], ['H', ( 0.,-0.5 ,-1. )], ['H', ( 0.,-0.5 ,-0. )], ['H', ( 0.,-0. ,-1. )], ['H', ( 1.,-0.5 , 0. )], ['H', ( 0., 1. , 1. )], ] mol.basis = {'H': 'sto-3g', 'O': '6-31g',} mol.charge = 1 mol.spin = 1 mol.build() m = scf.UHF(mol) ehf = m.scf() emc = kernel(umc1step.CASSCF(m, 4, (2,1)), m.mo_coeff, verbose=4)[1] print(ehf, emc, emc-ehf) print(emc - -2.9782774463926618) mol.atom = [ ['O', ( 0., 0. , 0. )], ['H', ( 0., -0.757, 0.587)], ['H', ( 0., 0.757 , 0.587)],] mol.basis = {'H': 'cc-pvdz', 'O': 'cc-pvdz',} mol.charge = 1 mol.spin = 1 mol.build() m = scf.UHF(mol) ehf = m.scf() mc = umc1step.CASSCF(m, 4, (2,1)) mc.verbose = 4 mo = addons.sort_mo(mc, m.mo_coeff, (3,4,6,7), 1) emc = mc.mc2step(mo)[0] print(ehf, emc, emc-ehf) print(emc - -75.5644202701263, emc - -75.573930418500652, emc - -75.574137883405612, emc - -75.648547447838951) mc = umc1step.CASSCF(m, 4, (2,1)) mc.verbose = 4 emc = mc.mc2step()[0] print(ehf, emc, emc-ehf) print(emc - -75.5644202701263, emc - -75.573930418500652, emc - -75.574137883405612, emc - -75.648547447838951)