1#
2#   CheMPS2: a spin-adapted implementation of DMRG for ab initio quantum chemistry
3#   Copyright (C) 2013-2018 Sebastian Wouters
4#
5#   This program is free software; you can redistribute it and/or modify
6#   it under the terms of the GNU General Public License as published by
7#   the Free Software Foundation; either version 2 of the License, or
8#   (at your option) any later version.
9#
10#   This program is distributed in the hope that it will be useful,
11#   but WITHOUT ANY WARRANTY; without even the implied warranty of
12#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13#   GNU General Public License for more details.
14#
15#   You should have received a copy of the GNU General Public License along
16#   with this program; if not, write to the Free Software Foundation, Inc.,
17#   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18#
19
20import numpy as np
21import sys
22import PyCheMPS2
23import ctypes
24
25# Set the seed of the random number generator and cout.precision
26Initializer = PyCheMPS2.PyInitialize()
27Initializer.Init()
28
29# Read in the FCIDUMP
30psi4group = 7 # d2h: see chemps2/Irreps.h
31filename  = b'../../tests/matrixelements/N2.CCPVDZ.FCIDUMP'
32orbirreps = np.array([-1, -1], dtype=ctypes.c_int) # CheMPS2 reads it in from FCIDUMP
33Ham = PyCheMPS2.PyHamiltonian( -1, psi4group, orbirreps, filename )
34
35# Define the symmetry sector
36TwoS = 0     # Two times the targeted spin
37N = 14       # The number of electrons
38Irrep = 0    # The targeted irrep
39
40# Define the CASSCF
41DOCC  = np.array([ 3, 0, 0, 0, 0, 2, 1, 1 ], dtype=ctypes.c_int) # see N2.ccpvdz.out
42SOCC  = np.array([ 0, 0, 0, 0, 0, 0, 0, 0 ], dtype=ctypes.c_int)
43NOCC  = np.array([ 1, 0, 0, 0, 0, 1, 0, 0 ], dtype=ctypes.c_int)
44NDMRG = np.array([ 4, 0, 1, 1, 0, 4, 1, 1 ], dtype=ctypes.c_int)
45NVIRT = np.array([ 2, 1, 2, 2, 1, 2, 2, 2 ], dtype=ctypes.c_int)
46theDMRGSCF = PyCheMPS2.PyCASSCF(Ham, DOCC, SOCC, NOCC, NDMRG, NVIRT)
47
48# Setting up the ConvergenceScheme
49OptScheme = PyCheMPS2.PyConvergenceScheme( 2 ) # 2 instructions
50OptScheme.set_instruction( 0,  500, 1e-10,  3, 0.1, 1e-5  )
51OptScheme.set_instruction( 1, 1000, 1e-10, 10, 0.0, 1e-10 )
52
53# Setting the DMRGSCFoptions and run DMRGSCF
54root_num = 1 # Ground state only
55theDMRGSCFoptions = PyCheMPS2.PyDMRGSCFoptions()
56theDMRGSCFoptions.setDoDIIS( True )
57theDMRGSCFoptions.setWhichActiveSpace( 2 ) # Localized orbitals
58IPEA = 0.0
59IMAG = 0.0
60PSEUDOCANONICAL = False
61Energy1 = theDMRGSCF.solve( N, TwoS, Irrep, OptScheme, root_num, theDMRGSCFoptions)
62Energy2 = theDMRGSCF.caspt2(N, TwoS, Irrep, OptScheme, root_num, theDMRGSCFoptions, IPEA, IMAG, PSEUDOCANONICAL)
63
64# Clean-up
65if theDMRGSCFoptions.getStoreUnitary():
66    theDMRGSCF.deleteStoredUnitary()
67if theDMRGSCFoptions.getStoreDIIS():
68    theDMRGSCF.deleteStoredDIIS()
69
70# The order of deallocation matters!
71del theDMRGSCFoptions
72del OptScheme
73del theDMRGSCF
74del Ham
75del Initializer
76
77# Check whether the test succeeded
78if (( np.fabs( Energy1 + 109.15104350802 ) < 1e-8 ) and ( np.fabs( Energy2 + 0.116979484098865 ) < 1e-8 )):
79    print("================> Did test 14 succeed : yes")
80else:
81    print("================> Did test 14 succeed : no")
82
83