Talk:Mod:Hunt Research Group/IL cpmd functional

Which functional to choose for [bmim]Cl using CPMD

Notes by Ling

1. My [bmim][BF4] uses BLYP

2. Barbara Kirchner's group:

Zah10: [CH3NH3][NO3] uses BP86 for [CH3NH3][NO3] and BLYP for water. Code: CPMD.

Tha09: 32 pairs [emim][SCN] uses PBE for [emim][SCN] and BLYP for water. Code: CP2K.

3. Del Popolo's group:

Pop07: 8 pairs [mmim][PF6]; 4 pairs [emim][PF6]; 2 pairs [bmim][PF6]; 8 pairs [ddmim][PF6] uses LDA or PBE. Code: SIESTA.

Pop05: 8 and 24 pairs [dmim]Cl uses PBE. Code: SIESTA.

Pop06: 8 pairs [dmim]Cl uses PBE. Code: SIESTA.

Pra06: 8 pairs [dmim]Cl uses PBE. Code: SIESTA.

4. Balasubramanian's group:

Bha07: 12 pairs [bmim][PF6] + 28 pairs CO2 uses BLYP. Code: CPMD.

fictitious electron mass of 700 a.u. (increasing the fictitious electron mass might lead to the need of more MD steps to have the electronic system equilibrated.

time step of 5 a.u. (around 0.12 fs)

cutoff 90 Ry

5. Others:

Gha07: 10 pairs [bmim]I. Code: CPMD. They haven't specified which functional!

Bag07: 9 and 20 pairs [emim]Cl uses PBE. Code: CPMD.

Buh05: 25 and 41 pairs [dmim]Cl uses BP86. Code: CPMD.

6. Conclusion:

Most GGAs have similar behaviours for most properties. So I would not expect big differences between BLYP, PBE, PW91, BP86, etc.

My simulation is most similar to Balasubramanian's Bha07. => Choose BLYP.