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exercises:2017_uzh_cp2k-tutorial:wfc [2017/07/07 14:27]
vrybkin [1. Task: Benzene dimer MP2 binding energy]
exercises:2017_uzh_cp2k-tutorial:wfc [2017/07/07 15:02]
vrybkin [1. Task: Benzene dimer MP2 binding energy]
Line 38: Line 38:
 FREE_HFX_BUFFER .FALSE. FREE_HFX_BUFFER .FALSE.
 </​code>​ </​code>​
 +
 +Perform two optimizations setting ''​FREE_HFX_BUFFER''​ to ''​.TRUE.''​ and ''​.FALSE.''​ Compare the overall timings and especially the times for performing Hartree-Fock exchange calculations:​
 +<​code>​
 +integrate_four_center ​              71 12.3    2.261    4.012  108.805 ​ 109.179
 +</​code>​
 +The last number in the line is the real time of execution. The memory distribution between the RI-MP2 integrals and HFX integrals are tuned by the ''​MEMORY''​ keyword in the ''&​WF_CORRELATION''​ section and the ''&​MEMORY''​ section in the ''&​HF''​ section:
 +<​code>​
 +&MEMORY
 +  MAX_MEMORY ​ 1800
 +&END
 +
 +</​code>​
 +
 +At the optimized (or the most optimized) geometry of benzene monomer perform a Hartree-Fock calculation to compare electron densities. Visualize them with VMD. Electron density difference between MP2 and HF looks as follows:
 +{{ :​exercises:​2017_uzh_cp2k-tutorial:​benzene_diff.png?​400 |}}
 + 
  
 ===== 2. Task: Benzene monomer RPA energy: frequency integration ===== ===== 2. Task: Benzene monomer RPA energy: frequency integration =====
Line 218: Line 234:
 &MOTION &MOTION
  &​GEO_OPT  &​GEO_OPT
-   ​OPTIMIZER BFGS ! Good choice for '​small'​ systems ​(use LBFGS for large systems) +   ​OPTIMIZER BFGS ! Good choice for '​small'​ systems ​like benzene
-   ​MAX_ITER ​ 100+
    ​MAX_DR ​   [bohr] 0.003 ! adjust target as needed    ​MAX_DR ​   [bohr] 0.003 ! adjust target as needed
    &​BFGS    &​BFGS
exercises/2017_uzh_cp2k-tutorial/wfc.txt · Last modified: 2017/07/13 15:44 by vrybkin