RI-MP2 Keywords in the Jaguar Input File

  • Overview
  • Examples

The rimp2 keyword allows you to request a resolution-of the identity Møller-Plesset perturbation theory (RI-MP2) calculation. By default, RI-MP2 is off. For more information on the RI-MP2 method, see RI-MP2 Calculations and Pseudospectral Resolution-of-the-identity MP2 Techniques. RI-MP2 keywords are given in Table 1.

Table 1. Keyword settings for RIMP2 calculations

Keyword

Value

Description

rimp2

0

Do not run a RI-MP2 calculation.

 

1

Run a RI-MP2 calculation.

rimp2_auxbas

see below

Specifies the auxiliary basis set to be used in a RI-MP2 calculation. By default, Jaguar automatically selects an auxiliary basis set based on the normal basis set. For example, if the normal basis set is cc-pvdz, then the cc-pvdz-rifit basis set is selected by default.

n_frozen_core

−1

Treats the core molecular orbitals as frozen in a RI-MP2 calculation. The number of core molecular orbitals is the sum of the numbers of atomic core orbitals. The number of atomic core orbitals are listed here.

 

0

No molecular orbitals are treated as frozen.

 

>0

The number of molecular orbitals with the lowest energies to be frozen.

n_frozen_virtual

0

No virtual orbitals are treated frozen by default.

 

>0

The number of virtual molecular orbitals with the highest orbitals energies to be frozen.

scs_ss

1

The default scaling factor for the MP2 same-spin correlation energy, which corresponds to not doing Spin Component Scaling.

 

>0

The scaling factor for the MP2 same-spin correlation energy.

scs_os

1

The default scaling factor for the MP2 opposite-spin correlation energy, which corresponds to not doing Spin Component Scaling.

 

>0

The scaling factor for the MP2 opposite-spin correlation energy.

Available Auxiliary Basis Sets

The available auxiliary basis set values for the rimp2_auxbas keyword are listed below:

  • cc-pvdz-rifit
  • cc-pvtz-rifit
  • cc-pvqz-rifit
  • aug-cc-pvdz-rifit
  • aug-cc-pvtz-rifit
  • aug-cc-pvqz-rifit
  • def2-sv(p)-rifit
  • def2-svp-rifit
  • def2-svpd-rifit
  • def2-tzvp-rifit
  • def2-tzvpd-rifit
  • def2-tzvpp-rifit
  • def2-tzvppd-rifit
  • def2-qzvp-rifit
  • def2-qzvpp-rifit
  • def2-qzvppd-rifit

Default Frozen Core Settings

The following table lists the number of atomic core orbitals used by Jaguar:

Atom # of frozen orbitals
H-He 0
Li-Ne 1
Na-Ar 5
K-Zn 9
Ga-Kr 14
Rb-Cd 18
In-Xe 23
Cs-Lu 27
Hf-Hg 34
Tl-Rn 39
Fr-Lr 43

By default, the RI-MP2 method uses an SCF wavefunction calculated with the pseudospectral method, which requires a basis set that is set up for the pseudospectral method—see Basis Sets for basis set information. If the SCF calculation is having convergence issues, you may want to set the scf_nops keyword to 1. This setting computes an analytic SCF wavefunction, which is generally more accurate than the pseudospectral SCF wavefunction. The pseudospectral method is still used in the calculation of RI-MP2 gradients.

Single Point Energy Examples

Note: The default RI setting will automatically invoke the corresponding dz-rifit auxiliary basis. The `frozen core` approximation is applied automatically. The low-energy 1s orbital of oxygen is frozen.

Example input file (ene-rimp2-0001.in):

&gen
rimp2=1
basis=cc-pvdz
&
&zmat
O1   0.0000000000      0.0000000000     -0.0667079824
H2   0.0000000000      0.7594973815      0.5293520449
H3   0.0000000000     -0.7594973815      0.5293520449
&

To submit the job from the command line, download the input file (below) and enter the following command:

$SCHRODINGER/jaguar run -jobname=ene_rimp2_0001 ene-rimp2-0001.in

Click a button to download the file. The Output files are those produced when the job is run.

Files generated with release version: 2025-3

Input file: ene-rimp2-0001.in
Output files

Example input file (ene-rimp2-0002.in):

&gen
rimp2=1
basis=cc-pvdz
molchg=1
multip=2
&
&zmat
C1            0.0000000000      0.0000000000      0.6017568300 
O2            0.0000000000      0.0000000000     -0.5977993196 
H3            0.0000000000      0.9710178674      1.1612467660 
H4            0.0000000000     -0.9710178674      1.1612467660 
&

To submit the job from the command line, download the input file (below) and enter the following command:

$SCHRODINGER/jaguar run -jobname=ene_rimp2_0002 ene-rimp2-0002.in

Click a button to download the file. The Output files are those produced when the job is run.

Files generated with release version: 2025-3

Input file: ene-rimp2-0002.in
Output files

Note: The term `all-electron` refers to correlating all of the electrons in the system in the MP2 calculation.

Example input file (ene-rimp2-0003.in):

&gen
rimp2=1
basis=cc-pvdz
rimp2_auxbas=cc-pvtz-rifit
n_frozen_core=0
&
&zmat
O1   0.0000000000      0.0000000000     -0.0667079824
H2   0.0000000000      0.7594973815      0.5293520449
H3   0.0000000000     -0.7594973815      0.5293520449
&

To submit the job from the command line, download the input file (below) and enter the following command:

$SCHRODINGER/jaguar run -jobname=ene_rimp2_0003 ene-rimp2-0003.in

Click a button to download the file. The Output files are those produced when the job is run.

Files generated with release version: 2025-3

Input file: ene-rimp2-0003.in
Output files