1 /*
2    CheMPS2: a spin-adapted implementation of DMRG for ab initio quantum chemistry
3    Copyright (C) 2013-2018 Sebastian Wouters
4 
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 2 of the License, or
8    (at your option) any later version.
9 
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13    GNU General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License along
16    with this program; if not, write to the Free Software Foundation, Inc.,
17    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19 
20 #ifndef TENSORX_CHEMPS2_H
21 #define TENSORX_CHEMPS2_H
22 
23 #include "Tensor.h"
24 #include "TensorL.h"
25 #include "TensorQ.h"
26 #include "TensorOperator.h"
27 #include "TensorF0.h"
28 #include "TensorF1.h"
29 #include "Problem.h"
30 #include "SyBookkeeper.h"
31 
32 namespace CheMPS2{
33 /** TensorX class.
34     \author Sebastian Wouters <sebastianwouters@gmail.com>
35     \date March 6, 2013
36 
37     The TensorX class is a storage and manipulation class for completely contracted Hamiltonian terms. */
38    class TensorX : public TensorOperator{
39 
40       public:
41 
42          //! Constructor
43          /** \param boundary_index The boundary index
44              \param moving_right If true: sweep from left to right. If false: sweep from right to left
45              \param denBK The symmetry bookkeeper with symmetry sector virtual dimensions
46              \param Prob The Problem containing the Hamiltonian matrix elements */
47          TensorX(const int boundary_index, const bool moving_right, const SyBookkeeper * denBK, const Problem * Prob);
48 
49          //! Destructor
50          virtual ~TensorX();
51 
52          //! Clear and add the relevant terms to the TensorX
53          /** \param denT TensorT from which the new TensorX should be made
54              \param Ltensors Array with the TensorL's
55              \param Xtensor The previous TensorX
56              \param Qtensor The previous TensorQ
57              \param Atensor The previous A-tensor
58              \param Ctensor The previous C-tensor
59              \param Dtensor The previous D-tensor */
60          void update(TensorT * denT, TensorL ** Ltensors, TensorX * Xtensor, TensorQ * Qtensor, TensorOperator * Atensor, TensorOperator * Ctensor, TensorOperator * Dtensor);
61 
62          //! Clear and add the relevant terms to the TensorX
63          /** \param denT TensorT from which the new TensorX should be made */
64          void update(TensorT * denT);
65 
66       private:
67 
68          //Problem containing the matrix elements
69          const Problem * Prob;
70 
71          //helper functions
72          void makenewRight(const int ikappa, TensorT * denT);
73          void makenewLeft(const int ikappa, TensorT * denT);
74          void addTermQLRight(const int ikappa, TensorT * denT, TensorL ** Lprev, TensorQ * Qprev, double * workmemRR, double * workmemLR, double * workmemLL);
75          void addTermQLLeft(const int ikappa, TensorT * denT, TensorL ** Lprev, TensorQ * Qprev, double * workmemLL, double * workmemLR, double * workmemRR);
76          void addTermALeft(const int ikappa, TensorT * denT, TensorOperator * Aprev, double * workmemLR, double * workmemLL);
77          void addTermARight(const int ikappa, TensorT * denT, TensorOperator * Aprev, double * workmemRR, double * workmemLR);
78          void addTermCRight(const int ikappa, TensorT * denT, TensorOperator * denC, double * workmemLR);
79          void addTermCLeft(const int ikappa, TensorT * denT, TensorOperator * denC, double * workmemLR);
80          void addTermDRight(const int ikappa, TensorT * denT, TensorOperator * denD, double * workmemLR);
81          void addTermDLeft(const int ikappa, TensorT * denT, TensorOperator * denD, double * workmemLR);
82 
83    };
84 }
85 
86 #endif
87