In the work by Parker et al. (TM Parker, LA Burns, RM Parrish, AG Ryno, CD Sherril, J. Chem. Phys… 2014, 140(9), 094106. DOI: 10.1063/1.4867135), some levels of SAPT are discussed (recommended as the gold, silver, and bronze standard of SAPT: SAPT2+(3)δMP2/aug-cc-pVTZ, SAPT2+/aug-cc-pVDZ, and sSAPT0/jun-ccpVDZ).
Could someone with experience suggest me some SAPT levels to calculate the interaction energy of dimer halogenated molecules derived from methane (e.g., CH3F, CH2F2, CF4, CFCl3…etc)?
Calculations with sSAPT0/jun-ccpVDZ (bronze standard) were successful (did not crash). I tried to perform calculations with SAPT2+/aug-cc-pVDZ (silver standard) but they always crashed because temporary files generated were too large.
I would like to know if there is any better level than sSAPT0/jun-ccpVDZ for calculating the interaction energy of halogenated dimers derived from methane.
Hi Emerson,
I’ve seen a paper, that I believe may answer your question. It has some SAPT calculations, so hopefully it’s useful. I’ve not read it yet, though:
It’s strange that your calculations with higher order SAPT crash - they must be for huge systems. Feel free to share the input, just in case it’s a bug. Perhaps a good DFT (such as wB97M-V) could get you decent interaction energies?
Ah, good, someone else has chimed in on the halogen issue — I’ve got no new info there. I would have suggested running a higher-order sapt job at double-zeta and triples-zeta on a representative system and checking at what sapt level it converges. Which is what you tried to do
I’m concerned that your >sapt0 job isn’t running. I hacked up the sapt4 test case to add F and Cl atoms (below), and sapt2+ ran in 15 min (psi4 sapt.in -n6). That’s on a reasonably beefy computer, but the 10 heavy atom systems you describe don’t sound extraordinary for a high-level sapt job. Make sure you give it a good amount of memory and threads, and feel free to post back the specific error and input file.
memory 20gb
molecule formamide_dimer {
0 1
C -2.018649 0.052883 0.000000
O -1.452200 1.143634 0.000000
N -1.407770 -1.142484 0.000000
Cl -1.964596 -1.977036 0.000000
Cl -0.387244 -1.207782 0.000000
Cl -3.117061 -0.013701 0.000000
--
0 1
C 2.018649 -0.052883 0.000000
O 1.452200 -1.143634 0.000000
N 1.407770 1.142484 0.000000
F 1.964596 1.977036 0.000000
F 0.387244 1.207782 0.000000
F 3.117061 0.013701 0.000000
units angstrom
}
set {
basis aug-cc-pvdz
df_basis_sapt aug-cc-pvdz-ri
df_basis_scf aug-cc-pvdz-jkfit
guess sad
scf_type df
puream true
print 1
basis_guess true
}
set sapt {
freeze_core true
}
energy('sapt2+')
Attached I send 2 example outputs for SAPT calculations for the 2 x CF4 molecules: cf4_1_1.dat (41.6 KB) cf4_1_2.dat (40.2 KB)
The cf4_1_1.out file would be the output of the sSAPT0/jun-ccpVDZ calculation for 2 x CF4.
The cf4_1_2.out file would be the output of the SAPT2+/aug-cc-pVDZ calculation for the 2 x CF4.
Both 2 SAPT cases (sSAPT0/jun-ccpVDZ and SAPT2+/aug-cc-pVDZ) were run on the same cluster with the following command: psi4 -i cf4_1_X.dat -o cf4_1_X.out -n 1.
SAPT2+/aug-cc-pVDZ calculations for CF4 gave problem related to lack of memory. Maybe I built my input incorrectly.
If anyone can kindly tell me what i did wrong or some probable solution, i would be grateful.
@loriab Maybe it’s a memory issue. psi4 starts by dedicating 500.0 MiB to 1 thread according to my script cf4_1_2.dat (461 Bytes)
and result cf4_1_2.dat (40.2 KB)
.
I completely missed that it’s substituted methane dimers - that should run on almost anything made in the last decade!
The memory line on the top of Lori’s reply is the key: memory 20gb
Generally you want to give Psi4 slightly less memory than either your physical memory or whatever you ask for in the job script, as there is an overhead. I usually give Psi4 90% of the memory that I request from the queueing system - so if you are running it on your local PC with 16 GB, give the job slightly less than that so your other apps won’t start crashing.
