Calcium polonide
Preferred IUPAC name
Calcium polonide
3D model (JSmol)
  • InChI=1S/Ca.Po/q+2;-2
  • [Ca+2].[Po-2]
Molar mass 249 g·mol−1
Density 6.0 g/cm3
Rock Salt (cubic)
Fm3m (No. 225)
a = 0.6514 nm
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Calcium polonide is an intermetallic compound with the chemical formula CaPo. It is made up of calcium and polonium. Rather than being found in nature, the compound is entirely synthetic, and difficult to study, due to polonium's high vapor pressure, radioactivity, and easy oxidation in air.


At atmospheric pressure, it crystalizes in the cubic rock salt crystal structure.[1] At a high pressure of around 16.7 GPa, the structure is predicted to transform to the caesium chloride-type crystal structure.[2]

Electronic properties

Based on theoretical calculations, calcium polonide is predicted to be a semiconductor.[3]

See also


  1. ^ a b Witteman, W. G.; Giorgi, A. L.; Vier, D. T. (1960). "The Preparation and Identification of Some Intermetallic Compounds of Polonium". The Journal of Physical Chemistry. American Chemical Society (ACS). 64 (4): 434–440. doi:10.1021/j100833a014. ISSN 0022-3654.
  2. ^ Shi, Liwei; Wu, Ling; Duan, Yifeng; Hao, Lanzhong; Hu, Jing; Yang, Xianqing; Tang, Gang (2012). "Band structure, phase transition, phonon and elastic instabilities in calcium polonide under pressure: A first-principles study". Solid State Communications. Elsevier BV. 152 (22): 2058–2062. Bibcode:2012SSCom.152.2058S. doi:10.1016/j.ssc.2012.08.028. ISSN 0038-1098.
  3. ^ Bhardwaj, Purvee; Singh, Sadhna (2015-06-09). "Phase transition and bulk properties of some polonide compounds: a comparative study". Phase Transitions. Informa UK Limited. 88 (9): 859–876. Bibcode:2015PhaTr..88..859B. doi:10.1080/01411594.2015.1020312. ISSN 0141-1594. S2CID 93331676.