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 pi.h 31 32 @brief Constants for the number pi and some related numbers like 33 sqrt(pi). 34 35 @author: Elias Rudberg <em>responsible</em> 36 */ 37 38 #ifndef PI_HEADER 39 #define PI_HEADER 40 41 #include "config.h" // need config.h to get PRECISION_QUAD_FLT128 macro 42 43 /* ELIAS NOTE 2016-08-30: the numbers below were produced using the 44 quadmath library, by running the program in 45 source/standalone/pi_quadmath.c */ 46 47 #ifdef PRECISION_QUAD_FLT128 48 49 /* __float128 case: use suffix 'Q' */ 50 #define pi 3.1415926535897932384626433832795028Q 51 #define sqrtpi 1.7724538509055160272981674833411451Q 52 #define pitopow52 17.4934183276248628462628216798715544Q 53 54 #else 55 56 /* regular, non-__float128 case: use suffix 'L' */ 57 #define pi 3.1415926535897932384626433832795028L 58 #define sqrtpi 1.7724538509055160272981674833411451L 59 #define pitopow52 17.4934183276248628462628216798715544L 60 61 #endif 62 63 #endif 64