Update README.md

README.md

@@ -39,7 +39,7 @@ $ ./mlcorr_prep.sh ch4
 # calculate MP2 MP3 MP4 energy density
 $ cd ../eneden/
 $ chmod +x eneden.sh
-$ ./eneden.sh ch4 # Here STDOUT will give the values of summing up of the energy density,
+$ ./eneden.sh ch4 # Here STDOUT will give the values of summing up of the energy density on each atom,
                 # which should equals to MPn correlation energy
 
 # calculate reference value:
@@ -48,7 +48,8 @@ $ psi4 -n 8 -i input.dat -o output.dat # you can find reference MP2, MP3, and MP
                                      # correlation energy in output.dat
 
 ```
-Results: contribution for each atom (Atomic Contribution)
+
+#### Results: contribution for each atom (Atomic Contribution)
 ```bash
 PT2: 
 C: -0.0713488682277866
@@ -87,7 +88,8 @@ qd.sphere.lebedev_031() -> qd.sphere.lebedev_011()
 
 # Others same with ch4_200_031
 ```
-Results: contribution for each atom (Atomic Contribution)
+
+#### Results: contribution for each atom (Atomic Contribution)
 ```bash
 PT2: 
 C: -0.0731792208782222
@@ -112,6 +114,55 @@ MP4(SDTQ): -0.118437326291
 ~3.5 mH deviation is too large, so this setting is **not recommended**.
 
 
+### h2
+This is to calculate energy density on Hydrogen atom of H2@cc-pvdz with grid settings:
+Legendre quadrature (200 radial points) and Lebedev quadrature (noted as 031, 350 angular points).
 
+```shell
+# prepare wavefunction and FCIDUMP files, here we use Psi4 package
+# one can also use other packages, e.g. PySCF, OpenMolcas
+$ cd examples/h2/calcu/
+$ psi4 -n 8 -i input.dat -o output.dat
+
+# convert molden format of wavefunction and txt format of FCIDUMP (in Psi 4 is INPDUMP)
+# into .npy files
+# Note that external package is needed to convert molden to .wfn first, we use molden2aim 
+# (https://github.com/zorkzou/Molden2AIM) for example.
+$ cd ../prep/
+$ chmod +x mlcorr_prep.sh
+$ ./mlcorr_prep.sh h2
+
+# calculate MP2 MP3 MP4 energy density
+$ cd ../eneden/
+$ chmod +x eneden.sh
+$ ./eneden.sh h2 # Here STDOUT will give the values of summing up of the energy density on each atom,
+                 # which should equals to MPn correlation energy
+
+# calculate reference value:
+$ cd ../ref/
+$ psi4 -n 8 -i input.dat -o output.dat # you can find reference MP2, MP3, and MP4
+                                       # correlation energy in output.dat
+```
+
+#### Results: contribution for each atom (Atomic Contribution)
+```bash
+PT2: 
+H: -0.0132622797812593
+PT3:
+H: -0.0031027482505314
+PT4:
+H: -0.0007878420821888
+
+Combine:
+MP2: -0.0265245595625186
+MP3: -0.0327300560635814
+MP4(SDTQ): -0.034305740227959
+
+Compare with reference correlation energy:
+MP2: -0.026443871885
+MP3: -0.032632881103
+MP4(SDTQ): -0.034205101033
+```
+~0.1 mH deviation.