### Author Topic: classical optimization and molecular dynamic  (Read 899 times)

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#### mohit.s

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##### classical optimization and molecular dynamic
« on: August 1, 2018, 22:12 »
Hi

A. Is classical optimization suitable for decorated carbon nanotube structures or should another method be used instead?
B. Which type of molecular dynamics is better to calculate adsorption energies in a wide range of temperatures with good accuracy?

Thanks

#### mlee

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##### Re: classical optimization and molecular dynamic
« Reply #1 on: August 2, 2018, 11:43 »
It depends on the ForceField parameters, system size, element types and your interesting topics and so on.
You can check your decorated carbon nanotube structure with ATK-ForceField.
If you need to make an equilibrium state in a range of constant temperatures, there are several methods of NVT and NPT.

#### mohit.s

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##### Re: classical optimization and molecular dynamic
« Reply #2 on: August 3, 2018, 17:57 »
Thank you for your prompt response.
A. Is calculations separately for each temperature should be done or in each MD calculation a temperature range can be monitored?
B. In separate calculations, which temperature is the temperature of the system? (Reservoir temperature, final temperature or temperature of initial velocity)?
Thanks

#### Ulrik G. Vej-Hansen

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##### Re: classical optimization and molecular dynamic
« Reply #3 on: August 6, 2018, 14:05 »

1. NVT means that the calculations are done at fixed temperature of the reservoir. If you wish to see the behavior of the system at different temperatures, you will need to run several distinct MD simulations. However, you can heat/cool the system in a single MD simulation if you wish to study that process.

2. The specified temperature is the temperature of the reservoir, while the temperature shown in analysis tools such as the Movie Tool is the system temperature. If this is significantly different from the specified temperature, there might be some problems in the simulation.