We are seeing problems with SCF convergence. Below is our input:

The job fails in the second cycle of the geometry optimization. With the RMS not decreasing after the 5th cycle.

I would have expected the guess to be reasonably good given that it is the second cycle of a a geometry optimization.

Could you also what the RMS refers to?

Thanks,

Alberto

SCF Guess: Orbitals guess was supplied from a previous computation.

==> Iterations <==

```
Total Energy Delta E RMS |[F,P]|
```

@DF-RKS iter 0: -13045.90536692229580 -1.30459e+04 3.85584e+01

@DF-RKS iter 1: 129882.97040010261117 1.42929e+05 6.27055e+01

@DF-RKS iter 2: 248919.32267033698736 1.19036e+05 1.28728e+02 DIIS

@DF-RKS iter 3: 157982.09611620506621 -9.09372e+04 6.74676e+01 DIIS

@DF-RKS iter 4: -1827.36715855029388 -1.59809e+05 7.71873e+01 DIIS

@DF-RKS iter 5: -77099.60978518263437 -7.52722e+04 7.49161e+00 DIIS

@DF-RKS iter 6: 94296.27326243813150 1.71396e+05 8.64587e+01 DIIS

@DF-RKS iter 7: 93922.84112911540433 -3.73432e+02 8.64498e+01 DIIS

@DF-RKS iter 8: 94657.99319289218693 7.35152e+02 8.64445e+01 DIIS

@DF-RKS iter 9: 94754.95497342936869 9.69618e+01 8.64630e+01 DIIS

@DF-RKS iter 10: 94734.97976389329415 -1.99752e+01 8.64920e+01 DIIS

@DF-RKS iter 11: 94318.07436000506277 -4.16905e+02 8.64808e+01 DIIS

@DF-RKS iter 12: 92988.96451654926932 -1.32911e+03 8.64337e+01 DIIS

@DF-RKS iter 13: 93538.08612074318808 5.49122e+02 8.64579e+01 DIIS

@DF-RKS iter 14: 93216.11399623805482 -3.21972e+02 8.64310e+01 DIIS

@DF-RKS iter 15: 93251.44370108740986 3.53297e+01 8.64036e+01 DIIS

@DF-RKS iter 16: 93235.18532787107688 -1.62584e+01 8.63755e+01 DIIS

@DF-RKS iter 17: 93052.87001873142435 -1.82315e+02 8.63830e+01 DIIS

…

@DF-RKS iter 88: 92497.03996290548821 -5.77013e-07 8.64194e+01 DIIS

@DF-RKS iter 89: 92497.03996170758910 -1.19790e-06 8.64194e+01 DIIS

@DF-RKS iter 90: 92497.03996050723072 -1.20036e-06 8.64194e+01 DIIS

@DF-RKS iter 91: 92497.03996213289793 1.62567e-06 8.64194e+01 DIIS

@DF-RKS iter 92: 92497.03996453451691 2.40162e-06 8.64194e+01 DIIS

@DF-RKS iter 93: 92497.03996091890440 -3.61561e-06 8.64194e+01 DIIS

@DF-RKS iter 94: 92497.03996165953868 7.40634e-07 8.64194e+01 DIIS

@DF-RKS iter 95: 92497.03996257559629 9.16058e-07 8.64194e+01 DIIS

@DF-RKS iter 96: 92497.03996206201555 -5.13581e-07 8.64194e+01 DIIS

@DF-RKS iter 97: 92497.03996133855253 -7.23463e-07 8.64194e+01 DIIS

@DF-RKS iter 98: 92497.03996161745454 2.78902e-07 8.64194e+01 DIIS

@DF-RKS iter 99: 92497.03996341893799 1.80148e-06 8.64194e+01 DIIS

@DF-RKS iter 100: 92497.03996035839373 -3.06054e-06 8.64194e+01 DIIS

optMethod = ‘M06-2X’

optBasis = ‘6-31g*’

finalMethod = ‘mp2’

finalBasis = ‘aug-cc-pv[dt]z’

import time

t1 = time.time()

def saveFile(name, string):

f=open(name,‘w’)

f.write(string)

f.close()

molecule rec1_pid15624 {

0 1

C -4.165000 -7.248000 -23.474001

C -1.554000 -7.924000 -24.099001

C -2.084000 -11.902000 -24.750999

C 0.298000 -12.262000 -24.895000

C -3.523000 -12.049000 -25.172001

C -1.610000 -6.023000 -20.294001

C -3.601000 -4.617000 -20.027000

N 0.229000 -10.282000 -20.840000

O 0.012000 -9.303000 -20.004000

C -0.788000 -8.390000 -20.474001

C -1.165000 -8.793000 -21.792000

C -0.457000 -10.064000 -21.955999

C -0.588000 -10.906000 -23.152000

C -2.043000 -8.143000 -22.813000

N -1.276000 -7.284000 -19.733000

C -3.356000 -7.825000 -22.506001

C -3.672000 -7.009000 -24.750000

C -2.358000 -7.343000 -25.073999

C -1.871000 -11.125000 -23.632000

C -0.992000 -12.469000 -25.393999

C 0.500000 -11.483000 -23.768000

O 1.755000 -11.321000 -23.219999

O -1.132000 -13.175000 -26.555000

O -4.493000 -6.441000 -25.698000

C -4.084000 -6.443000 -27.018999

C -2.317000 -5.067000 -19.391001

O -1.132000 -5.684000 -21.379000

C -2.421000 -3.705000 -19.997999

C -6.225000 -12.085000 -25.705000

N -5.483000 -11.018000 -26.054001

C -4.162000 -10.956000 -25.757000

C -5.657000 -13.191000 -25.009001

C -4.316000 -13.155000 -24.698999

C -3.740000 -14.247000 -23.993000

C -4.532000 -15.347000 -23.635000

C -5.895000 -15.384000 -23.957001

C -6.469000 -14.316000 -24.636000

H -5.194300 -6.989300 -23.234100

H -0.523800 -8.171100 -24.352400

H 1.149100 -12.714500 -25.398300

H -3.903700 -5.024900 -20.985701

H -4.436000 -4.390200 -19.372400

H -1.236900 -7.357400 -18.722300

H -3.763800 -8.018400 -21.515900

H -1.918300 -7.168600 -26.050600

H -2.733500 -10.726800 -23.098301

H 1.676700 -10.945700 -22.316999

H -2.083800 -13.262400 -26.765301

H -4.913200 -6.079800 -27.635401

H -3.245900 -5.757900 -27.187500

H -3.842500 -7.449300 -27.380301

H -2.270400 -5.192100 -18.320200

H -1.935900 -3.468800 -20.938900

H -2.452900 -2.856100 -19.321699

H -7.276000 -12.058000 -25.976801

H -3.640000 -10.047900 -26.037701

H -2.684000 -14.269600 -23.732700

H -4.081900 -16.183599 -23.101700

H -6.499200 -16.243401 -23.672701

H -7.528500 -14.337000 -24.884899

no_com

no_reorient

}

memory 8 Gb

set basis $optBasis

set scf guess read

set opt_coordinates cartesian

set optking dynamic_level 1

set GEOM_MAXITER 200

optE, optWfn = optimize(optMethod, return_wfn=True)

t2 = time.time()

set basis $finalBasis

finalE = energy(cbs, scf_wfn=‘scf’, corl_wfn=‘mp2’, corl_basis=finalBasis, crol_schemme=corl_xtpl_helgaker_2)

t3 = time.time()

saveFile(‘psi4.wall.time.log’, ‘OptTime = %d\nSPTime = %d\nTotalTime = %d\n’ %(t2-t1,t3-t2,t3-t1))

saveFile(‘psi4.optimized.geometry.log’, optWfn.molecule().save_string_xyz_file())

saveFile(‘psi4.optimized.energy.log’, str(optE))

saveFile(‘psi4.opt.energy.type.log’, optMethod+’/’+optBasis)

saveFile(‘psi4.final.energy.log’, str(finalE))

saveFile(‘psi4.final.energy.type.log’, finalMethod+’/’+finalBasis)