.. index:: single: Program; Averd single: Averd .. _UG\:sec\:averd: :program:`averd` ================ .. only:: html .. contents:: :local: :backlinks: none .. _UG\:sec\:averd_description: Description ----------- .. xmldoc:: %%Description: Computes average densities and corresponding natural molecular orbitals :program:`Averd` computes average densities and corresponding natural molecular orbitals. Given a set of density matrices in the same basis set, an average density matrix is constructed and diagonalized to give average natural orbitals. These orbitals have non-integer occupation numbers, although they usually are fairly well clustered in one strongly occupied part and one weakly occupied part. From basic mathematical properties of natural orbitals, a truncated set of the orbitals constructed this way constitutes the most compact basis of one-electron functions of that given size. In other words, the smallest set of functions to span the average space within a certain accuracy has been obtained. :program:`Averd` is in essence very similar to :program:`Genano`. .. _UG\:sec\:averd_dependencies: Dependencies ------------ :program:`Averd` needs a set of input densities. Any of the programs, which generate a density must precede. .. _UG\:sec\:averd_files: Files ----- Below is a list of the files that are used/created by :program:`Averd`. Input files ........... .. class:: filelist :file:`RUNFILE` File for communication of auxiliary information generated by the program :program:`SEWARD`. :file:`ONEINT` File with one-electron integrals generated by :program:`SEWARD`. :file:`RUN***` A set of RunFiles on which a density matrix is stored. This density matrix is read and added to the average. If :kword:`ORBItals` is given, these files are not needed. :file:`NAT***` A set of orbitals in the format generated by :program:`SCF` or :program:`RASSCF`. The orbitals are used to generate a density matrix, which is added to the average. Only required if :kword:`ORBItals` is given. Output files ............ .. class:: filelist :file:`AVEORB` The average orbitals generated by :program:`Averd`. They are stored in the same way as SCF-orbitals and can be used as INPORB. .. _UG\:sec\:averd_input: Input ----- .. class:: keywordlist :kword:`TITLe` Title of the calculation. .. xmldoc:: %%Keyword: Title Title of the calculation :kword:`WSET` Followed by two rows. On the first the number of input orbitals are given, :math:`N`. Second row contains :math:`N` numbers each giving a weight for the :math:`k`\th input density matrix to the average density. The weights are normalized by :program:`Averd`, hence only the ratio of the numbers have any significance. **This keyword is mandatory.** .. xmldoc:: %%Keyword: WSet Number of input sets of orbitals and relative weight for each of them. :kword:`PRINt` Print level. 1 is default. Higher than 3 is not recommended for the average user. .. xmldoc:: %%Keyword: Print Print level. Default is 1. :kword:`ORBItals` This keyword signifies that the densities should be created from average orbitals in the files :file:`NAT***`, not directly from the density matrices on the files :file:`RUN***`. The default is to use the density matrices on :file:`RUN***`. .. xmldoc:: %%Keyword: Orbitals This keyword signifies that the densities should be created from average orbitals in the NAT*** files, not directly from the density matrices in the RUN*** files. :kword:`OCCUpation` Followed by one number. The number of average orbitals with an occupation higher than this number is reported for each symmetry. Since the occupation is the guide for how to truncate the orbitals in subsequent applications, this is an easy way to get hold of that number. The default is :math:`10^{-5}`. .. xmldoc:: %%Keyword: Occupation The number of average orbitals with an occupation higher than this number is reported for each symmetry. The default is 1.0d-5. Input example ............. In this example, two density matrices are averaged and their average orbitals are computed. :: &Seward Basis set O.ano-s.Pierloot.10s6p3d.7s4p2d. O 0.0000 0.0000 0.3000 End of Basis set Basis set H.ano-s.Pierloot.7s3p.4s1p. H1 0.0000 -1.4300 -0.8070 H2 0.0000 1.4300 -0.8070 End of Basis Set &FfPt Dipo z 0.005 End of Input &Scf Occupation 5 >>COPY $Project.RunFile RUN001 &FfPt Dipo z -0.005 &Scf Occupation 5 End of Input >>COPY $Project.RunFile RUN002 &Averd &End Wset 2 1.0 1.0 Occupation 1d-6 .. xmldoc::