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sc::MBPT2_R12(3)		     MPQC		      sc::MBPT2_R12(3)

NAME
       sc::MBPT2_R12 - The MBPT2_R12 class implements several linear R12
       second-order perturbation theory	methods.

SYNOPSIS
       #include	<mbptr12.h>

       Inherits	sc::MBPT2.

   Public Member Functions
       MBPT2_R12 (StateIn &)
       MBPT2_R12 (const	Ref< KeyVal > &)
	   The KeyVal constructor.
       void save_data_state (StateOut &)
	   Save	the base classes (with save_data_state)	and the	members	in the
	   same	order that the StateIn CTOR initializes	them.
       Ref< GaussianBasisSet > aux_basis () const
       Ref< GaussianBasisSet > vir_basis () const
       bool gbc	() const
       bool ebc	() const
       LinearR12::ABSMethod abs_method () const
       LinearR12::StandardApproximation	stdapprox () const
       bool spinadapted	() const
       R12IntEvalInfo::StoreMethod r12ints_method () const
       const std::string & r12ints_file	() const
       double corr_energy ()
       double r12_corr_energy ()
       RefSymmSCMatrix density ()
	   Returns the SO density.
       void obsolete ()
	   Marks all results as	being out of date.
       int gradient_implemented	() const
       int value_implemented ()	const
	   Information about the availability of values, gradients, and
	   hessians.
       void print (std::ostream	&o=ExEnv::out0()) const
	   Print information about the object.

   Protected Member Functions
       void compute ()
	   Recompute at	least the results that have compute true and are not
	   already computed.

   Additional Inherited	Members
Detailed Description
       The MBPT2_R12 class implements several linear R12 second-order
       perturbation theory methods.

Constructor & Destructor Documentation
   sc::MBPT2_R12::MBPT2_R12 (const Ref<	KeyVal > &)
       The KeyVal constructor.

       gbc
	   This	boolean	specifies whether Generalized Brillouin	Condition
	   (GBC) is assumed to hold. The default is 'true'. This keyword is
	   only	valid if stdapprox=A'. The effect of setting this keyword to
	   true	is rather small	-- hence it is not recommended to use this
	   keyword.

       ebc
	   This	boolean	specifies whether Extended Brillouin Condition (EBC)
	   is assumed to hold. The default is 'true'. This keyword is only
	   valid if stdapprox=A'. The effect of	setting	this keyword to	true
	   is rather small -- hence it is not recommended to use this keyword.

       stdapprox
	   This	gives a	string that must take on one of	the values below. The
	   default is A'.

       A   Use second order M/ller-Plesset perturbation	theory with linear R12
	   terms in standard approximation A (MP2-R12/A). Only energies	can be
	   computed with the MP2-R12/A method.

       A'  Use second order M/ller-Plesset perturbation	theory with linear R12
	   terms in standard approximation A' (MP2-R12/A'). This will cause
	   MP2-R12/A energies to be computed also. Only	energies can be
	   computed with the MP2-R12/A'	method.

       B   Use second order M/ller-Plesset perturbation	theory with linear R12
	   terms in standard approximation B. This method is not implemented
	   yet.

       spinadapted
	   This	boolean	specifies whether to compute spin-adapted or spin-
	   orbital pair	energies. Default is to	compute	spin-adapted energies.

       aux_basis
	   This	specifies the auxiliary	basis to be used for the resolution of
	   the identity. Default is to use the same basis as for the orbital
	   expansion.

       vir_basis
	   This	specifies the basis to be used for the virtual orbitals.
	   Default is to use the same basis as for the orbital expansion.

       include_mp1
	   This	specifies whether to compute MP1 correction to the MP2 and
	   MP2-R12 energies. This option only has effect if vir_basis is not
	   the same as basis. MP1 correction is	a perturbative estimate	of the
	   difference between the HF energy computed in	vir_basis and basis.
	   Usually, it is a very poor estimate -- therefore this keyword
	   should be avoided by	non-experts. Default is	false.

       abs_method
	   This	string specifies whether the old ABS method, introduced	by
	   Klopper and Samson, or the new ABS variant, CABS, introduced	by
	   Valeev, should be used. Valid values	are 'ABS' (Klopper and
	   Samson), 'ABS+', 'CABS', and	'CABS+', where the '+' labels a	method
	   where the union of OBS and ABS is used to construct the RI basis.
	   The default is 'ABS'. The default in	2.3.0 and later	will be
	   'CABS+'.

       lindep_tol
	   The tolerance used to detect	linearly dependent basis functions in
	   the RI basis	set. The precise meaning depends on the
	   orthogonalization method. The default value is 1e-8.

       r12ints
	   This	specifies how to store transformed MO integrals. Valid values
	   are:

       mem-posix
	   Store integrals in memory for single-pass situations	and in a
	   binary file on task 0's node	using POSIX I/O	for multipass
	   situations. posix is	usually	less efficient than mpi	for
	   distributed parallel	multipass runs since the I/O is	performed by
	   one task only. However, this	method is guaranteed to	work in	all
	   types of environments, hence	mem-posix is the default.

       posix
	   Store integrals in a	binary file on task 0's	node using POSIX I/O.
	   This	method is different from mem-posix in that it forces the
	   integrals out to disk even if they could be stored in memory. posix
	   should only be used for benchmarking	and testing purposes.

       mem-mpi
	   Store integrals in memory for single-pass situations	and in a
	   binary file using MPI-I/O for multipass situations. This method
	   assumes the availability of MPI-I/O.	mem-mpi	is the preferred
	   choice in distributed environments which have MPI-I/O available.

       mpi
	   Store integrals in a	binary file using MPI-I/O. This	method is
	   different from mem-mpi in that it forces the	integrals out to disk
	   even	if they	could be stored	in memory. mpi should only be used for
	   benchmarking	and testing purposes.

       mem
	   Store integrals in memory. Can only be used with single-pass
	   transformations for MP2-R12/A and MP2-R12/A'	methods. This method
	   should only be used for testing purposes.

       If r12ints is not specified, then mem-posix method will be used.	If
       user wishes to use MPI-I/O, pending its availability, for higher
       parallel	efficiency, r12ints should be explicitly set to	mem-mpi.

       r12ints_file
	   This	specifies the prefix for the transformed MO integrals file if
	   r12ints is set to posix, mpi, mem-posix or mem-mpi is used. Default
	   is './<i>inputbasename</i>.r12ints',	where inputbasename is the
	   name	of the input file without '.in'. If MPI-I/O is used then it is
	   user's responsibility to ensure that	the file resides on a file
	   system that supports	MPI-I/O.

       twopdm_grid_aa
	   This	optional keyword specifies a TwoBodyGrid object	which to use
	   for coordinates at which to compute alpha-alpha part	of 2-PDM.

       twopdm_grid_ab
	   This	optional keyword specifies a TwoBodyGrid object	which to use
	   for coordinates at which to compute alpha-beta part of 2-PDM.

Member Function	Documentation
   void	sc::MBPT2_R12::compute () [protected],	[virtual]
       Recompute at least the results that have	compute	true and are not
       already computed. This should only be called by Result's	members.

       Reimplemented from sc::MBPT2.

   void	sc::MBPT2_R12::obsolete	() [virtual]
       Marks all results as being out of date. Any subsequent access to
       results will cause Compute::compute() to	be called.

       Reimplemented from sc::MBPT2.

   void	sc::MBPT2_R12::save_data_state (StateOut &) [virtual]
       Save the	base classes (with save_data_state) and	the members in the
       same order that the StateIn CTOR	initializes them. This must be
       implemented by the derived class	if the class has data.

       Reimplemented from sc::MBPT2.

   int sc::MBPT2_R12::value_implemented	() const [virtual]
       Information about the availability of values, gradients,	and hessians.

       Reimplemented from sc::MBPT2.

Author
       Generated automatically by Doxygen for MPQC from	the source code.

Version	2.3.1			Mon Jul	3 2017		      sc::MBPT2_R12(3)

NAME | SYNOPSIS | Detailed Description | Constructor & Destructor Documentation | Member Function Documentation | Author

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