Ehrenfest Molecular Dynamics

Dear all,

I am running nonadiabatic molecular dynamics on a Cobalt Porphyrin system using Ehrenfest dynamics in Q-Chem. The frequency calculation completes successfully, but the dynamics job terminates at the line:

“State following based on attachment/detachment density analysis”

This occurs at TIME STEP #0 immediately after the warm-up steps.

I observe the same behavior when using both:
Ehrenfest MD
Symmetric Quasi-Classical Meyer–Miller (SQC/MM) dynamics

Interestingly, the Q-Chem sample jobs run without any issues.
There is no explicit error message — the job simply stops after the state-following analysis line.

Has anyone encountered a similar issue? Any suggestions on what might cause termination at the initial time step?

Thank you for your help.

$rem
JOBTYPE freq
METHOD PBE0
BASIS 6-31G*
THRESH 14
MEM_TOTAL 240000
MEM_STATIC 4000
SCF_MAX_CYCLES 200
$end

@@@

$molecule
read
$end

$rem
JOBTYPE aimd
EXCHANGE PBE0
BASIS 6-31G*
MEM_TOTAL 240000
MEM_STATIC 4000
SYM_IGNORE true
AIMD_STEPS 1000 ! Typically more would be used
TIME_STEP 20
AIMD_PRINT 1
AIMD_INIT_VELOC thermal
AIMD_METHOD qcmd !initiates quasi-classical nonadiabatic dynamics
QCMD_METHOD ehrenfest
QCMD_INITNUC boltzmann !sample from a Boltzmann distribution
AIMD_TEMP 300 ! K
AIMD_INTEGRATION vverlet
SQC_GAMADJUST true
QCMD_INITSTATE 19
SCF_MAX_CYCLES 500
THRESH 14
SCF_CONVERGENCE 7
CIS_N_ROOTS 30
CIS_SINGLETS false
CIS_TRIPLETS true
RPA 0
$end

I think I ran into a similar issue before… I believe you cannot run Ehrenfest dynamics with too many states. Try with, say, 5 just to see if it runs.