[CP2K-user] MD calculation of NPT_F ensemble including baro- and thermostats at various T

Lukas C l.cvi... at gmail.com
Mon Nov 16 11:03:48 UTC 2020


Hi everyone!

I am trying to see signs of melting for a given SiO2 bulk. In order to 
achieve this, I ran MD calculations for a NPT_F (constant pressure and 
temperature, flexible cell) ensemble which is connected to a thermal bath 
(adaptive langevin thermostat) and to a barostat which are utilized to keep 
T and p at constant values for each simulation respectively. The 
temperature was set to T=600K,900K,1200K,1500K,1800K,2100K and 3000K. 

However, i am experiencing multiple problems.
1. The calculations abort after 20 steps (every time) with the error:

 *******************************************************************************
 *   
___                                                                       *
 *  /   
\                                                                      *
 * 
[ABORT]                                                                     
*
 *  \___/                  invalid value for enumeration:   
104                *
 *    
|                                                                        *
 *  
O/|                                                                        *
 * /| 
|                                                                        *
 * / \                                     
input/input_enumeration_types.F:188 *
 *******************************************************************************

2. by comparing the output files, i found out that the simulation seems to 
trigger the same reactions (altough the temperature is very different). 
cp2k did recognice the temperature (thus, the kinetic energy is changed) 
but the curves that represent the change of kinetic energy resemble each 
other perfectly. to my understanding, this means that exactly the same 
reactions were triggered, which should not be the case for different 
temperatures. Each simulation was started with a .wfn file as an initial 
guess, which was taken from an single-point ENERGY calculation that was 
conducted beforehand. Thus the potential energy is the same for each 
simulation at t=0. The plot is attached together with the input file. I 
already tried to use various optimizers, preconditioners and so on. am i 
doing something seriously wrong? Thank you, your help is appreciated!

Regards,
Lukas
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