Hello,
I am running a simple ROHF calculation on the W20 dianion using the 6-311++G**+H(s) basis set to follow with a EOM-EE-MP2 job
Using the attached input file, Q-Chem gives the following results:
Nuclear Repulsion Energy = 2353.0399823917 hartrees
E(SCF) = -1521.10032860
However, using the same basis set and coordinates in CFOUR, I obtain:
NUCLEAR REPULSION ENERGY: 2353.0394897083 a.u.
E(ROHF) = -1521.10034092542673
I am a bit confused, since both calculations were run in the correct Ci symmetry, and in Q-Chem I set unrestricted = false to enforce ROHF. I initially thought the discrepancy might be due to using a contracted basis set in Q-Chem, but using the uncontracted version leads to the same discrepancy.
I also don’t believe the issue is how I massage the SCF procedure in CFOUR, since the discrepancy appears even in the nuclear repulsion energy.
Thank you for your help!
- Q-chem input
$molecule
-2 1
O 0.81970390 3.76180188 1.46198421
H 1.25733314 3.57623864 0.60662586
H 1.28053058 3.15236640 2.08985186
O 3.23531149 0.32384416 0.82599793
H 2.28704679 0.24534129 0.54501863
H 3.49730856 -0.60763578 1.01618688
O 2.12038214 1.83018807 3.06713251
H 2.71678728 1.43075505 2.40256623
H 1.39368615 1.16573414 3.09435004
O 1.67889978 2.66759777 -1.09845507
H 1.31345759 1.81126453 -0.75488271
H 0.97978370 2.95012344 -1.72374558
O 4.03170854 1.18133322 -1.78319056
H 3.32970052 1.86297519 -1.75980377
H 3.97661340 0.83597026 -0.86530409
O -0.95148381 2.86761049 -2.33075086
H -1.07366672 2.76925194 -1.36379456
H -0.72502626 1.94837269 -2.61441428
O 2.44423083 -0.83761865 -3.02570310
H 3.05470385 -0.16291434 -2.64493233
H 2.25681964 -1.43877987 -2.27814630
O -0.16320877 0.18675191 -2.66773044
H 0.75486481 -0.07288729 -2.93729087
H -0.14033978 0.07651131 -1.66791290
O -1.40160789 2.29458293 0.60787206
H -0.93199048 1.42618076 0.40724019
H -0.68720703 2.86686792 1.00101251
O 3.69931899 -2.47696211 1.11052040
H 3.13116201 -2.68488228 1.87264116
H 3.07256270 -2.57733255 0.36267269
O -2.44423083 0.83761865 3.02570310
H -3.05470385 0.16291434 2.64493233
H -2.25681964 1.43877987 2.27814630
O 0.95148381 -2.86761049 2.33075086
H 1.07366672 -2.76925194 1.36379456
H 0.72502626 -1.94837269 2.61441428
O 0.16320877 -0.18675191 2.66773044
H -0.75486481 0.07288729 2.93729087
H 0.14033978 -0.07651131 1.66791290
O -3.69931899 2.47696211 -1.11052040
H -3.13116201 2.68488228 -1.87264116
H -3.07256270 2.57733255 -0.36267269
O 1.40160789 -2.29458293 -0.60787206
H 0.93199048 -1.42618076 -0.40724019
H 0.68720703 -2.86686792 -1.00101251
O -4.03170854 -1.18133322 1.78319056
H -3.32970052 -1.86297519 1.75980377
H -3.97661340 -0.83597026 0.86530409
O -1.67889978 -2.66759777 1.09845507
H -1.31345759 -1.81126453 0.75488271
H -0.97978370 -2.95012344 1.72374558
O -3.23531149 -0.32384416 -0.82599793
H -2.28704679 -0.24534129 -0.54501863
H -3.49730856 0.60763578 -1.01618688
O -0.81970390 -3.76180188 -1.46198421
H -1.25733314 -3.57623864 -0.60662586
H -1.28053058 -3.15236640 -2.08985186
O -2.12038214 -1.83018807 -3.06713251
H -2.71678728 -1.43075505 -2.40256623
H -1.39368615 -1.16573414 -3.09435004
$end
$rem
UNRESTRICTED FALSE
METHOD eom-mp2
BASIS gen
EE_SINGLETS [6,6]
EE_TRIPLETS [6,6]
SYMMETRY true
PURECART 1
SCF_ALGORROTH DIIS
THRESH 14
S2THRESH 16
$end
$basis
H 0
S 3 1.00
33.86500 0.0254938
5.094790 0.190373
1.158790 0.852161
S 1 1.00
0.325840 1.000000
S 1 1.00
0.102741 1.000000
S 1 1.00
0.0360000 1.0000000
S 1 1.00
0.0090000 1.0000000
P 1 1.00
0.750 1.000000
****
O 0
S 6 1.00
8588.500 0.00189515
1297.230 0.0143859
299.2960 0.0707320
87.37710 0.2400010
25.67890 0.5947970
3.740040 0.2808020
SP 3 1.00
42.11750 0.113889 0.0365114
9.628370 0.920811 0.237153
2.853320 -0.00327447 0.819702
SP 1 1.00
0.905661 1.000000 1.000000
SP 1 1.00
0.255611 1.000000 1.000000
SP 1 1.00
0.0845000 1.0000000 1.0000000
D 1 1.00
1.292 1.000000
****
$end
- CFOUR input (ZMAT)
*CFOUR(CALC=MP2
EXCITE=EOMEE
ESTATE_CONV=7
ABCDTYPE=AOBASIS
ESTATE_SYM=3/3
BASIS=SPECIAL
REF=ROHF
COORD=CARTESIAN
SCF_MAXCYC=1050
FROZEN_CORE=ON
MEMORY=100000, MEM_UNIT=MB
SUBGROUP=4
UNITS=ANGSTROM
OCCUPATION=51-50/51-50
SCF_DAMPING=500
SCF_EXPORDER=25
CHARGE=-2
MULTIPLICITY=1)
- CFOUR input (GENBAS)
H:6-311++G**
VTZ Valence Triple Zeta: 3 Funct.'s/Valence AO with diffuse+polarization on all atoms
2
0 1
5 1
7 1
33.86500 5.094790 1.158790 0.325840 0.102741 0.0360000 0.009
0.0254938 0.00000000 0.00000000 0.00000000 0.00000
0.190373 0.00000000 0.00000000 0.00000000 0.00000
0.852161 0.00000000 0.00000000 0.00000000 0.00000
0.00000000 1.000000 0.00000000 0.00000000 0.00000
0.00000000 0.00000000 1.000000 0.00000000 0.00000
0.00000000 0.00000000 0.00000000 1.0000000 0.00000
0.00000000 0.00000000 0.00000000 0.0000000 1.00000
0.750
1.000000
O:6-311++G**
VTZ Valence Triple Zeta: 3 Funct.'s/Valence AO with diffuse+polarization on all atoms
3
0 1 2
5 4 1
12 6 1
8588.500 1297.230 299.2960 87.37710 42.11750
25.67890 9.628370 3.740040 2.853320 0.905661
0.255611 0.0845000
0.00189515 0.00000000 0.00000000 0.00000000 0.00000000
0.0143859 0.00000000 0.00000000 0.00000000 0.00000000
0.0707320 0.00000000 0.00000000 0.00000000 0.00000000
0.2400010 0.00000000 0.00000000 0.00000000 0.00000000
0.00000000 0.113889 0.00000000 0.00000000 0.00000000
0.5947970 0.00000000 0.00000000 0.00000000 0.00000000
0.00000000 0.920811 0.00000000 0.00000000 0.00000000
0.2808020 0.00000000 0.00000000 0.00000000 0.00000000
0.00000000 -0.00327447 0.00000000 0.00000000 0.00000000
0.00000000 0.00000000 1.000000 0.00000000 0.00000000
0.00000000 0.00000000 0.00000000 1.000000 0.00000000
0.00000000 0.00000000 0.00000000 0.00000000 1.0000000
42.11750 9.628370 2.853320 0.905661 0.255611
0.0845000
0.0365114 0.00000000 0.00000000 0.00000000
0.237153 0.00000000 0.00000000 0.00000000
0.819702 0.00000000 0.00000000 0.00000000
0.00000000 1.000000 0.00000000 0.00000000
0.00000000 0.00000000 1.000000 0.00000000
0.00000000 0.00000000 0.00000000 1.0000000
1.292
1.000000