Use Spartan or WebMO to optimize the structure of the following molecule with B3LYP  theory with 6-31+G(d). Notice that different multiplicity might cause different structures, compare the energies of the structures too.

Data link:Google Drive

1. use multiplicity=singlet to optimize the structure

2. use multiplicity=triplet to optimize the structure

Plot the electron density of He and He- and use MP2 theory with d-aug-cc-pVTZ and aug-cc-pVTZ basis sets.

Step

1. Use the keyword < Density=All > in my Input file.

2. In Linux system use command < formchk > to transform Checkpoint file to  FormCheckpoint file.

3. Use command < cubegen > to creat cube file

4. Transfrom cube file to dat file can  be more easy to make graph.

1.use MP2/aug-cc-pVTZ

2. use MP2/d-aug-cc-pVTZ

2. compare the difference between two different basis set