|  |  | 
               
                  |  | POTENTIAL_TYPE {Keyword} | 
               
                  |  | Which interaction potential should be used (Coulomb, TShPSC operator). | 
               
                  |  | This keyword cannot be repeated
                     and it expects
                     
                     precisely one keyword. | 
               
                  |  | Default value:
                     COULOMB | 
               
                  |  | List of valid keywords: 
                        
                           
                              COULOMBCoulomb potential: 1/r
                           
                              TSHPSCTShPSC:1/x - s/Rc for x ≤ Rc(1 - s)/Rc - (x - Rc)/Rc^2 + (x - Rc)^2/Rc^3
                                    - (2*n^2 - 7*n + 9 - 4*s)*(x - Rc)^3/(Rc^4*(n^2 - 2*n + 1)*(n - 1)) + (6-3*s - 4*n
                                    + n^2)*(x - Rc)^4/(Rc^5*(n^4 - 4*n^3 + 6*n^2 - 4*n + 1)) for Rc < x ≤ n*Rc (4th
                                    order polynomial)0 for x > n*Rc
 |