Dear Q-Chem users,

I have been running calculations in Q-Chem 5.4 since about a month, so I can’t qualify myself as an expert user, but I am noticing an unexpected behavior with my calculations and I’m trying to backtrack the issue to understand its roots.

I noticed that frequently, in my SCF calculations, the variational energy goes up in the very initial steps, instead of going down as I would expect. Up to now, I’m doing only preliminary calculations with DFT (wB97M-V and PBE-D3), I cannot see any apparent issue with the other calculation parameters and this happens even with molecules as small as benzene. Below you can find the most relevant parts of my input, and a brief example of the output section in which the problem is showing up.

```
$rem
JOBTYPE Opt
METHOD PBE
DFT_D D3
BASIS def2-SVP
SYM_IGNORE = TRUE
$end
$comment
test calculation to understand the energy is frequently going up in the 1st step of the SCF procedure
$end
$molecule
0 1
C -7.01922 1.35094 -0.00000
C -5.96370 2.18760 -0.00000
C -4.71137 1.69182 -0.00000
C -4.51456 0.35937 -0.00000
C -5.57009 -0.47728 -0.00000
C -6.82242 0.01850 -0.00000
H -8.02920 1.75077 -0.00000
H -6.12242 3.26218 -0.00000
H -3.86011 2.36656 -0.00000
H -3.50459 -0.04046 -0.00000
H -5.41137 -1.55186 0.00000
H -7.67367 -0.65625 -0.00000
$end
```

in the output:

```
Exchange: PBE Correlation: PBE
Using SG-1 standard quadrature grid
Dispersion: Grimme D3
using 4 threads for integral computing
-------------------------------------------------------
OpenMP Integral computing Module
Release: version 1.0, May 2013, Q-Chem Inc. Pittsburgh
-------------------------------------------------------
A restricted SCF calculation will be
performed using DIIS
SCF converges when DIIS error is below 1.0e-08
---------------------------------------
Cycle Energy DIIS error
---------------------------------------
1 -233.1291008905 7.83e-02
2 -231.5491219665 1.02e-02 <--- here you can see how the energy is going up!
3 -231.3921405812 1.42e-02
4 -231.7568518085 8.07e-04
```

I want to kindly thank everybody reading for your time!