MD Temperature Ramp not Working

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graham_pritchard
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MD Temperature Ramp not Working

#1 Post by graham_pritchard » Fri Feb 03, 2023 5:36 pm

Hi,

I am new to running ab-initio MD simulations with VASP. I am struggling to understand why the following does not result in a temperature change over the course of the simulation?

I have set MDALGO=2 and smass=-1 but the result is a simulation with a constant temperature of 3900K--the same at the starting temperature. TEEND seems to have no effect.

I am using VASP 6.3.2

INCAR created by Atomic Simulation Environment
ENCUT = 400.000000
POTIM = 2.000000
SIGMA = 0.150000
SMASS = -1.000000
TEBEG = 3900.000000
TEEND = 2000.000000
EDIFF = 1.00e-06
ALGO = fast
GGA = PE
PREC = normal
IBRION = 0
ISIF = 2
ISMEAR = 0
ISYM = 0
NELM = 100
NELMIN = 5
NSW = 2000
NWRITE = 2
MDALGO = 2
NBLOCK = 10
LCHARG = .FALSE.
LWAVE = .TRUE.
LREAL = Auto

ferenc_karsai
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Re: MD Temperature Ramp not Working

#2 Post by ferenc_karsai » Sun Feb 05, 2023 8:25 am

As the wiki page wiki/index.php/SMASS writes SMASS=-1 will lead to a microcanonical ensemble in the intermediate.

Please try SMASS=1.0 or 2.0.

huangjs
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Re: MD Temperature Ramp not Working

#3 Post by huangjs » Tue Feb 20, 2024 10:40 pm

You can comment out MDALGO=2 and try again.
Temperature should ramp down for your simulation.

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