Package ffx.utilities

Class Constants

java.lang.Object
ffx.utilities.Constants
public class Constants extends Object
Library class containing constants such as Avogadro's number.

SI units: kg, m, s, C, K, mol, lm

Our typical units: g/mol, Angstrom, psec, elementary charges (+1 proton charge), K, mol, N/A

Since:
1.0
Author:
Jacob M. Litman, Michael J. Schnieders

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final double
    ANG_TO_NM
    Constant ANG_TO_NM=0.1
    static final double
    ATM_TO_BAR
    Constant ATM_TO_BAR=1.01325
    static final double
    AVOGADRO
    Avogadro's number, defining the mol.
    static final double
    BOHR
    Conversion from Bohr to Angstroms.
    static final double
    BOHR2
    Conversion from Bohr^2 to Angstroms^2.
    static final double
    BOLTZMANN_SI
    Boltzmann's constant in J/K, defining the Kelvin.
    static final double
    DEFAULT_ELECTRIC
    Coulomb constant in units of kcal*Ang/(mol*electron^2)
    static final double
    DEGREES_PER_RADIAN
    Degrees per radian.
    static final long
    DEL_V_Cs_SI
    Hyperfine transition frequency of cesium in Hertz, defining the second.
    static final double
    dWater
    Permittivity of water at STP.
    static final double
    ELEC_ANG_TO_DEBYE
    Conversion from electron-Angstroms to Debye.
    static final double
    ELEC_ANG2_TO_BUCKINGHAMS
    Conversion from electron-Angstroms^2 to Buckinghams.
    static final double
    ELECTRIC_CODATA_2018
    Coulomb constant in units of kcal*Ang/(mol*electron^2), as derived from CODATA 2018 permittivity of free space measured at 8.8541878128*10^-12 F/m ELECTRIC_CODATA_2018=332.063713299
    static final double
    ELEMENTARY_CHARGE_SI
    Elementary charge in Coulombs, defining the Coulomb.
    static final double
    FSEC_TO_PSEC
    Constant FSEC_TO_PSEC=0.001
    static final double
    HARTREE_TO_KCAL_PER_MOL
    Convert Hartree to kcal/mol.
    static final int
    K_CD_SI
    Luminous efficacy in lm/W, defining the lumen.
    static final double
    kB
    Boltzmann/ideal gas constant in units of g*Ang^2/(mol*psec^2*K).
    static final double
    KCAL_TO_GRAM_ANG2_PER_PS2
    Conversion from kcal/mole to g*Ang**2/ps**2.
    static final double
    KCAL_TO_KJ
    Constant KCAL_TO_KJ=4.184
    static final double
    KG_TO_GRAMS
    Constant KG_TO_GRAMS=1000
    static final double
    KJ_TO_KCAL
    Constant KJ_TO_KCAL=1.0 / KCAL_TO_KJ
    static final double
    LITERS_PER_CUBIC_ANGSTROM
    Constant LITERS_PER_CUBIC_ANGSTROM=1E-30
    static final double
    METERS_TO_ANG
    Constant METERS_TO_ANG=1E10
    static final double
    NM_TO_ANG
    Constant NM_TO_ANG=10
    static final double
    NS2SEC
    Convert nanoseconds to seconds.
    static final double
    PLANCK_CONSTANT_SI
    Planck constant in J*s, defining the kilogram (by defining the derived Joule).
    static final double
    PRESCON
    Conversion from kcal/mol/Ang^3 to Atm.
    static final double
    PSEC_TO_FSEC
    Constant PSEC_TO_FSEC=1000
    static final double
    R
    Ideal gas constant in kcal/(mol*K) R = BOLTZMANN_SI * AVOGADRO * 0.001 * KJ_TO_KCAL R = 0.0019872042586408316
    static final double
    ROOM_TEMPERATURE
    Room temperature ~= 298.15 Kelvins.
    static final double
    SEC_TO_PSEC
    Constant SEC_TO_PSEC=1E12
    static final int
    SPEED_OF_LIGHT_SI
    Speed of light in m/s, defining the meter.

  • Method Summary

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • DEL_V_Cs_SI

      public static final long DEL_V_Cs_SI
      Hyperfine transition frequency of cesium in Hertz, defining the second.

      DEL_V_Cs_SI = 9192631770L

      See Also:

    • SPEED_OF_LIGHT_SI

      public static final int SPEED_OF_LIGHT_SI
      Speed of light in m/s, defining the meter.

      SPEED_OF_LIGHT_SI = 299792458

      See Also:

    • PLANCK_CONSTANT_SI

      public static final double PLANCK_CONSTANT_SI
      Planck constant in J*s, defining the kilogram (by defining the derived Joule).

      PLANCK_CONSTANT_SI = 6.62607015E-34d

      See Also:

    • ELEMENTARY_CHARGE_SI

      public static final double ELEMENTARY_CHARGE_SI
      Elementary charge in Coulombs, defining the Coulomb.

      ELEMENTARY_CHARGE_SI = 1.602176634E-19d

      See Also:

    • BOLTZMANN_SI

      public static final double BOLTZMANN_SI
      Boltzmann's constant in J/K, defining the Kelvin.

      BOLTZMANN_SI = 1.380649E-23d

      See Also:

    • AVOGADRO

      public static final double AVOGADRO
      Avogadro's number, defining the mol.

      AVOGADRO = 6.02214076E23d

      See Also:

    • K_CD_SI

      public static final int K_CD_SI
      Luminous efficacy in lm/W, defining the lumen.

      K_CD_SI = 683

      See Also:

    • LITERS_PER_CUBIC_ANGSTROM

      public static final double LITERS_PER_CUBIC_ANGSTROM
      Constant LITERS_PER_CUBIC_ANGSTROM=1E-30
      See Also:

    • ATM_TO_BAR

      public static final double ATM_TO_BAR
      Constant ATM_TO_BAR=1.01325
      See Also:

    • KCAL_TO_KJ

      public static final double KCAL_TO_KJ
      Constant KCAL_TO_KJ=4.184
      See Also:

    • KJ_TO_KCAL

      public static final double KJ_TO_KCAL
      Constant KJ_TO_KCAL=1.0 / KCAL_TO_KJ
      See Also:

    • METERS_TO_ANG

      public static final double METERS_TO_ANG
      Constant METERS_TO_ANG=1E10
      See Also:

    • NM_TO_ANG

      public static final double NM_TO_ANG
      Constant NM_TO_ANG=10
      See Also:

    • ANG_TO_NM

      public static final double ANG_TO_NM
      Constant ANG_TO_NM=0.1
      See Also:

    • SEC_TO_PSEC

      public static final double SEC_TO_PSEC
      Constant SEC_TO_PSEC=1E12
      See Also:

    • KG_TO_GRAMS

      public static final double KG_TO_GRAMS
      Constant KG_TO_GRAMS=1000
      See Also:

    • PSEC_TO_FSEC

      public static final double PSEC_TO_FSEC
      Constant PSEC_TO_FSEC=1000
      See Also:

    • FSEC_TO_PSEC

      public static final double FSEC_TO_PSEC
      Constant FSEC_TO_PSEC=0.001
      See Also:

    • R

      public static final double R
      Ideal gas constant in kcal/(mol*K) R = BOLTZMANN_SI * AVOGADRO * 0.001 * KJ_TO_KCAL R = 0.0019872042586408316
      See Also:

    • kB

      public static final double kB
      Boltzmann/ideal gas constant in units of g*Ang^2/(mol*psec^2*K). kB = BOLTZMANN_SI * KG_TO_GRAMS * METERS_TO_ANG * METERS_TO_ANG * AVOGADRO / (SEC_TO_PSEC * SEC_TO_PSEC) kB = 0.831446261815324
      See Also:

    • PRESCON

      public static final double PRESCON
      Conversion from kcal/mol/Ang^3 to Atm. PRESCON=6.85684112e4
      See Also:

    • dWater

      public static final double dWater
      Permittivity of water at STP. dWater=78.3
      See Also:

    • NS2SEC

      public static final double NS2SEC
      Convert nanoseconds to seconds. NS2SEC=1e-9
      See Also:

    • ROOM_TEMPERATURE

      public static final double ROOM_TEMPERATURE
      Room temperature ~= 298.15 Kelvins. ROOM_TEMPERATURE=298.15
      See Also:

    • ELECTRIC_CODATA_2018

      public static final double ELECTRIC_CODATA_2018
      Coulomb constant in units of kcal*Ang/(mol*electron^2), as derived from CODATA 2018 permittivity of free space measured at 8.8541878128*10^-12 F/m ELECTRIC_CODATA_2018=332.063713299
      See Also:

    • DEFAULT_ELECTRIC

      public static final double DEFAULT_ELECTRIC
      Coulomb constant in units of kcal*Ang/(mol*electron^2)

      Note -- this value varies slightly between force field definitions and can be set using the ELECTRIC property. As such, it's not updated to SI/CODATA standards, but rather kept up-to-date with the coulomb parameter in Tinker/source/units.f. At present, the Tinker value is a truncated version of the Coulomb constant derived from CODATA 2018. DEFAULT_ELECTRIC=332.0637133

      See Also:

    • ELEC_ANG_TO_DEBYE

      public static final double ELEC_ANG_TO_DEBYE
      Conversion from electron-Angstroms to Debye. ELEC_ANG_TO_DEBYE=4.80321
      See Also:

    • ELEC_ANG2_TO_BUCKINGHAMS

      public static final double ELEC_ANG2_TO_BUCKINGHAMS
      Conversion from electron-Angstroms^2 to Buckinghams. ELEC_ANG2_TO_BUCKINGHAMS = ELEC_ANG_TO_DEBYE * ELEC_ANG_TO_DEBYE
      See Also:

    • KCAL_TO_GRAM_ANG2_PER_PS2

      public static final double KCAL_TO_GRAM_ANG2_PER_PS2
      Conversion from kcal/mole to g*Ang**2/ps**2. KCAL_TO_GRAM_ANG2_PER_PS2=4.1840e2
      See Also:

    • BOHR

      public static final double BOHR
      Conversion from Bohr to Angstroms. BOHR=0.529177210903
      See Also:

    • BOHR2

      public static final double BOHR2
      Conversion from Bohr^2 to Angstroms^2. BOHR2 = BOHR * BOHR
      See Also:

    • HARTREE_TO_KCAL_PER_MOL

      public static final double HARTREE_TO_KCAL_PER_MOL
      Convert Hartree to kcal/mol.
      See Also:

    • DEGREES_PER_RADIAN

      public static final double DEGREES_PER_RADIAN
      Degrees per radian.
      See Also: