For diatomic molecules , a systematic study using a minimum basis set and the first calculation with a larger basis set were published by Ransil and Nesbet respectively in 1960 .
For molecules with two atoms , a systematic study using a minimum basis set and the first calculation with a larger basis set were published by Ransil and Nesbet respectively in 1960 .
In 1970 , Ford asked Weslake and Co to build the BDA Engine for them , and by the end of 1970 the production line had been installed at Rye and production was under way .