Questions tagged [aimd]

Questions about ab-initio molecular dynamics (AIMD).

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18
votes
3answers
647 views

What are the types of ab initio Molecular Dynamics?

I am new to the world of Molecular Dynamics, and am curious to know exactly what is considered to be an ab initio Molecular Dynamics (AIMD) method, and how do they work? The seminal work by Roberto ...
11
votes
1answer
148 views

How would one find a material's equilibrium structure at any specific temperature?

Let's take an example of a simple FCC material, a binary alloy. Above absolute zero K, the alloy will start to disorder and become an FCC solid solution. The alloy would develop defects as it ...
10
votes
2answers
188 views

What are some methods for modeling bulk phase infrared spectra?

I am interested in predicting the infrared spectra of bulk phase molecules, it seems that AIMD (ab initio molecular dynamics) is the current best approach. I have found a tutorial on using CP2K to do ...
10
votes
2answers
91 views

Choosing RAM, CPU time, # of cores, and other parameters for an MD run

I did an AIMD run in VASP using 64 cores (32 cores/node) and 250 GB of memory (125 GB/node) for 5 ps (1 fs time step). The calculation took 12.6 hours to complete. CPU efficiency was 99.7% and memory ...
9
votes
1answer
346 views

AIMD and velocity scaling in VASP

Typically one does velocity scaling to "heat" their sample with MD. How do we do this in VASP? Is it by setting the SMASS=-1 and ...
7
votes
2answers
59 views

How to take periodic snapshots while running a simulation in VASP?

Same question, rephrased: What is the procedure to take snapshots at fixed intervals while running an AIMD or DFT Simulation in VASP? OR Which parameter in the INCAR file do I modify to achieve ...
7
votes
2answers
216 views

What is the real reason behind the minimization of the system at the beginning of a Car-Parrinello MD calculation?

I've been studying MD and more specifically about Car-Parrinello Molecular Dynamics and I'm not entirely sure if I understood the meaning behind the minimization. This is the way I understand it: The ...
7
votes
0answers
157 views

How to build amorphous Al2O3 using the AIMD method implemented in VASP?

I want to build amorphous Al$_2$O$_3$ with the AIMD (ab-initio molecular dynamics) method implemented in VASP. I know that two procedures should be taken into account, namely 1st: melt 2nd: quench ...
6
votes
0answers
27 views

Steps to obtain ionic diffusivity using AIMD

I read a paper and the authors wrote they use AIMD to estimate the ionic diffusivity of materials. I wonder steps to obtain the value at different temperatures. What are the input and output of ...