PhysicalConstants.h

Go to the documentation of this file.

// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2007 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#pragma once
 
#include <cmath>
 
// NAN is not defined in Visual C++ < 2013
#if (defined(_MSC_VER) && (_MSC_VER <= 1800))
#define INFINITY (DBL_MAX + DBL_MAX)
#define NAN (INFINITY - INFINITY)
#endif
 
namespace Mantid {
 
namespace PhysicalConstants {
static constexpr double N_A = 6.02214179e23;
 
static constexpr double h = 6.62606896e-34;
 
static constexpr double h_bar = h / (2 * M_PI);
 
static constexpr double g = 9.80665;
 
static constexpr double NeutronMass = 1.674927211e-27;
 
static constexpr double NeutronMassAMU = 1.008664916;
 
static constexpr double AtomicMassUnit = 1.660538921e-27;
 
static constexpr double meV = 1.602176487e-22;
 
static constexpr double meVtoWavenumber = 8.06554465;
 
static constexpr double meVtoFrequency = 0.2417989262;
 
static constexpr double meVtoKelvin = 11.604519;
 
static constexpr double E_mev_toNeutronWavenumberSq =
    1.0e20 * h_bar * h_bar / (2 * NeutronMass * meV); //[meV*Angstrom^2]
 
static constexpr double MuonLifetime = 2.1969811e-6;
 
static constexpr double StandardAtmosphere = 101.325;
 
static constexpr double BoltzmannConstant = 8.6173324e-02;
 
static constexpr double MuonGyromagneticRatio = 0.01355342;
 
} // namespace PhysicalConstants
} // namespace Mantid