1# -*- coding: utf-8 -*- 

2# 

3# This file is part of cclib (http://cclib.github.io), a library for parsing 

4# and interpreting the results of computational chemistry packages. 

5# 

6# Copyright (C) 2017, the cclib development team 

7# 

8# The library is free software, distributed under the terms of 

9# the GNU Lesser General Public version 2.1 or later. You should have 

10# received a copy of the license along with cclib. You can also access 

11# the full license online at http://www.gnu.org/copyleft/lgpl.html. 

12 

13"""Analyses related to orbitals.""" 

14 

15import logging 

16 

17import numpy 

18 

19from cclib.method.calculationmethod import Method 

20 

21 

22class Orbitals(Method): 

23 """A class for orbital related methods.""" 

24 

25 def __init__(self, data, progress=None, \ 

26 loglevel=logging.INFO, logname="Log"): 

27 

28 self.required_attrs = ('mocoeffs','moenergies','homos') 

29 # Call the __init__ method of the superclass. 

30 super(Orbitals, self).__init__(data, progress, loglevel, logname) 

31 self.fragresults = None 

32 

33 def __str__(self): 

34 """Return a string representation of the object.""" 

35 return "Orbitals" 

36 

37 def __repr__(self): 

38 """Return a representation of the object.""" 

39 return "Orbitals" 

40 

41 def closed_shell(self): 

42 """Return Boolean indicating if system is closed shell.""" 

43 

44 # If there are beta orbitals, we can assume the system is closed 

45 # shell if the orbital energies are identical within numerical accuracy. 

46 if len(self.data.mocoeffs) == 2: 

47 precision = 10e-6 

48 return numpy.allclose(*self.data.moenergies, atol=precision) 

49 

50 # Restricted open shell will have one set of MOs but two HOMO indices, 

51 # and the indices should be different (otherwise it's still closed shell). 

52 if len(self.data.homos) == 2 and self.data.homos[0] != self.data.homos[1]: 

53 return False 

54 

55 return True