1 /* Ergo, version 3.8, a program for linear scaling electronic structure
2  * calculations.
3  * Copyright (C) 2019 Elias Rudberg, Emanuel H. Rubensson, Pawel Salek,
4  * and Anastasia Kruchinina.
5  *
6  * This program is free software: you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation, either version 3 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  *
19  * Primary academic reference:
20  * Ergo: An open-source program for linear-scaling electronic structure
21  * calculations,
22  * Elias Rudberg, Emanuel H. Rubensson, Pawel Salek, and Anastasia
23  * Kruchinina,
24  * SoftwareX 7, 107 (2018),
25  * <http://dx.doi.org/10.1016/j.softx.2018.03.005>
26  *
27  * For further information about Ergo, see <http://www.ergoscf.org>.
28  */
29 
30 /** @file basis_func_pair_list.h
31 
32     @brief Functions for setting up lists of non-negligible basis
33     function pairs, for 2-electron integrals.
34 
35     @author: Elias Rudberg <em>responsible</em>
36 */
37 
38 #ifndef BASIS_FUNC_PAIR_LIST_HEADER
39 #define BASIS_FUNC_PAIR_LIST_HEADER
40 
41 #include <vector>
42 
43 #include "realtype.h"
44 #include "integral_info.h"
45 #include "basisinfo.h"
46 
47 typedef struct
48 {
49   int index_1;
50   int index_2;
51 } basis_func_index_pair_struct;
52 
53 int
54 get_basis_func_pair_list_2el(const BasisInfoStruct & basisInfo,
55 			     const IntegralInfo & integralInfo,
56 			     ergo_real threshold,
57 			     ergo_real maxDensityMatrixElement,
58 			     std::vector<basis_func_index_pair_struct>  & resultList);
59 
60 
61 #endif
62