Differences

This shows you the differences between two versions of the page.

--- exercises:2017_uzh_cp2k-tutorial:wfc [2017/07/07 14:27] – [1. Task: Benzene dimer MP2 binding energy] vrybkin
+++ exercises:2017_uzh_cp2k-tutorial:wfc [2020/08/21 10:15] (current) – external edit 127.0.0.1
@@ Line 38: / Line 38: @@
 FREE_HFX_BUFFER .FALSE.
 </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.
+ Density differences can be computed with ''cubecruncher'' available in the executable directory.
 ===== 2. Task: Benzene monomer RPA energy: frequency integration =====
@@ Line 218: / Line 233: @@
 &MOTION
  &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
    &BFGS