text: For ionic compounds, the standard enthalpy of formation is equivalent to the sum of several terms included in the Born–Haber cycle. For example, the formation of lithium fluoride,
  may be considered as the sum of several steps, each with its own enthalpy (or energy, approximately): 
  # , the standard enthalpy of atomization (or sublimation) of solid lithium.
  # , the first ionization energy of gaseous lithium.
  # , the standard enthalpy of atomization (or bond energy) of fluorine gas.
  # , the electron affinity of a fluorine atom.
  # , the lattice energy of lithium fluoride.
  The sum of these enthalpies give the standard enthalpy of formation () of lithium fluoride:
  In practice, the enthalpy of formation of lithium fluoride can be determined experimentally, but the lattice energy cannot be measured directly. The equation is therefore rearranged to evaluate the lattice energy: