Ha vers cal convertisseur - Hartree vers Calorie

Conversion derivation

Express both Ha and cal in the same base unit J (joule), then cancel the shared base unit.

1. 1

   Rewrite Ha in the base unit

   $$1\mathrm{Ha}=4.35974472\times 10^{-18}\mathrm{J}$$
2. 2

   Rewrite cal in the base unit

   $$1\mathrm{cal}=4.184\mathrm{J}$$
3. 3

   Forward conversion

   $$\begin{array}{rl}1\mathrm{Ha}& =\frac{4.35974472\times 10^{-18}\cancel{\mathrm{J}}}{4.184\cancel{\mathrm{J}}}\times 1\mathrm{cal}\\ & =\frac{4.35974472\times 10^{-18}}{4.184}\mathrm{cal}\\ & =1.042004\times 10^{-18}\mathrm{cal}\end{array}$$
4. 4

   Reverse conversion

   $$\begin{array}{rl}1\mathrm{cal}& =\frac{4.184\cancel{\mathrm{J}}}{4.35974472\times 10^{-18}\cancel{\mathrm{J}}}\times 1\mathrm{Ha}\\ & =\frac{4.184}{4.35974472\times 10^{-18}}\mathrm{Ha}\\ & =9.59689217\times 10^{17}\mathrm{Ha}\end{array}$$