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 boysfunction.h 31 32 @brief Code for Boys function evaluation. 33 34 @author: Elias Rudberg <em>responsible</em> 35 */ 36 37 #ifndef BOYSFUNCTION_HEADER 38 #define BOYSFUNCTION_HEADER 39 40 #include <vector> 41 #include "realtype.h" 42 #include "polydegree.h" 43 44 #include "config.h" // Needed to get the PRECISION_QUAD_FLT128 macro 45 46 /* We need Boys functions up to a degree 4 times the highest degree of basis functions. */ 47 #define BOYS_N_MAX (BASIS_FUNC_POLY_MAX_DEGREE*4+1) 48 49 /* Tune things differently depending on required precision. */ 50 #if defined(PRECISION_QUAD_FLT128) 51 #define BOYS_X_MAX 120.0 52 #define BOYS_TAB_DEGREE 12 53 #define BOYS_NO_OF_INTERVALS 1600 54 #elif defined(PRECISION_LONG_DOUBLE) 55 #define BOYS_X_MAX 85.0 56 #define BOYS_TAB_DEGREE 10 57 #define BOYS_NO_OF_INTERVALS 300 58 #else 59 #define BOYS_X_MAX 75.0 60 #define BOYS_TAB_DEGREE 10 61 #define BOYS_NO_OF_INTERVALS 200 62 #endif 63 64 typedef struct { 65 ergo_real midx; 66 ergo_real A[BOYS_TAB_DEGREE]; 67 } BoysFuncIntervalStruct; 68 69 typedef struct { 70 BoysFuncIntervalStruct list[BOYS_NO_OF_INTERVALS]; 71 } BoysFuncIntervalSetStruct; 72 73 class BoysFunctionManager { 74 private: 75 std::vector<BoysFuncIntervalSetStruct> Boys_list; 76 ergo_real SavedPrefactor_list[BOYS_N_MAX]; 77 int Boys_init_flag; 78 ergo_real BoysFunction_pretabulated(int n, ergo_real x) const; 79 public: 80 BoysFunctionManager(); 81 void init(); 82 ergo_real BoysFunction(int n, ergo_real x) const; 83 ergo_real BoysFunction_expensive(int n, ergo_real x, int noOfIntegrationIntervals, int method = 0) const; 84 // Stuff needed for Chunks&Tasks usage 85 void write_to_buffer ( char * dataBuffer, size_t const bufferSize ) const; 86 size_t get_size() const; 87 void assign_from_buffer ( char const * dataBuffer, size_t const bufferSize); 88 }; 89 90 #endif 91