howto:gemc
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howto:gemc [2015/07/14 18:53] – [What is GEMC] 130.18.126.175 | howto:gemc [2020/08/21 10:15] – external edit 127.0.0.1 | ||
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- | ==== What is GEMC ==== | + | ==== What is GEMC ?==== |
- | In the most common set up of Gibbs Ensemble Monte Carlo (GEMC) simulation, 2 boxes are utilized to represent vapor and liquid phases. In order to equilibrate the system, | + | In the most common set up of Gibbs Ensemble Monte Carlo (GEMC) simulation, 2 boxes are utilized to represent vapor and liquid phases. In order to equilibrate the system, different types of moves are used: |
- | \\ 1)Translations, | + | \\ 1) Translations, |
- | 2)Volume exchanges \\ | + | 2) Volume exchanges \\ |
- | 3)Particle | + | 3) Particle |
The particles are swapped between boxes to equilibrate the chemical potential, volume moves equilibrate pressure, and the rest of the moves within a box are performed to maintain thermal equilibrium. The main advantage of the GEMC simulation is that coexisting phases can be simulated without a physical interface using a unified partition function. Thus, we used GEMC simulations to determined vapor-liquid coexistence curves for a system. | The particles are swapped between boxes to equilibrate the chemical potential, volume moves equilibrate pressure, and the rest of the moves within a box are performed to maintain thermal equilibrium. The main advantage of the GEMC simulation is that coexisting phases can be simulated without a physical interface using a unified partition function. Thus, we used GEMC simulations to determined vapor-liquid coexistence curves for a system. | ||
==== Files required to run GEMC==== | ==== Files required to run GEMC==== | ||
- | In order to run GEMC certain input files are needed; the two main input files for each box {{gemc_nvt_box1.inp.zip}}{{gemc_nvt_box2.inp.zip}}, | + | In order to run GEMC certain input files are needed; the two main input files for each box {{gemc_nvt_box1.inp.zip}}{{gemc_nvt_box2.inp.zip}}, |
==== Sample of input files==== | ==== Sample of input files==== | ||
- | Starting with the input gem_nvt_box1.inp file first, we note that the location of the basis set file, as well as the potential file, is declared( in this case these two files are present in the current working directory). ''& | + | Starting with the input gemc_nvt_box1.inp file first, we note that the location of the basis set file, as well as the potential file, is declared(in this case these two files are present in the current working directory). ''& |
& | & | ||
METHOD Quickstep | METHOD Quickstep | ||
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SCF_GUESS ATOMIC | SCF_GUESS ATOMIC | ||
&END SCF | &END SCF | ||
- | One can increase the SCF iteration | + | One can increase the SCF iterations |
&XC | &XC | ||
& | & | ||
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&END XC_GRID | &END XC_GRID | ||
&END XC | &END XC | ||
- | The code snippet below declares the cell and cell ref size. | + | The cell and cell ref of the box 1 in angstorms. |
&CELL | &CELL | ||
ABC 13.7151207699 13.7151207699 13.7151207699 | ABC 13.7151207699 13.7151207699 13.7151207699 | ||
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POTENTIAL GTH-BLYP-q1 | POTENTIAL GTH-BLYP-q1 | ||
&END KIND | &END KIND | ||
- | declares the basis set intended to be used for the simulation. | + | declares the basis set(TZV2P) |
The following code | The following code | ||
&GLOBAL | &GLOBAL | ||
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RESTART_FILE_NAME mc_restart_2 | RESTART_FILE_NAME mc_restart_2 | ||
- | The '' | + | The '' |
The line '' | The line '' | ||
==== Sample of output files==== | ==== Sample of output files==== | ||
- | Sample output files for 64 H< | + | Sample output files for 64 H< |
- | As the input file for Box 1 and Box2 has already been explained above, we will not go into further detail{{gemc_nvt_box1.inp.zip}}{{gemc_nvt_box2.inp.zip}}. We include a topology file, | + | |
| BOX 1 | | | BOX 1 | | ||
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howto/gemc.txt · Last modified: 2024/01/03 13:07 by oschuett