Calcium dihydride

  • Formula: CaH2
  • Hill system formula: Ca1H2
  • CAS registry number: [7789-78-8]
  • Formula weight: 42.094
  • Class: hydride
  • Colour: white or grey
  • Appearance: crystalline solid
  • Melting point: 816°C (under hydrogen gas)
  • Boiling point:
  • Density: 1700 kg m-3

The following are some synonyms of calcium dihydride:

  • calcium dihydride
  • calcium(II) hydride
  • calcium dihydride

The oxidation number of calcium in calcium dihydride is 2.


Calcium hydride may be made by the reaction of calcium metal with hydrogen gas.

Ca(s) + H2(aq) (heat) → CaH2(s)

Solid state structure

  • Geometry of calcium:
  • Prototypical structure: CdI2

Crystal structure of calcium dihydride

Element analysis

The table shows element percentages for CaH2 (calcium dihydride).

Element %
Ca 95.21
H 4.79

Isotope pattern for CaH2

The chart below shows the calculated isotope pattern for the formula CaH2 with the most intense ion set to 100%.


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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