The word "Krakatit" is taken from Krakatoa, the volcano near Java, Indonesia which erupted and created what is believed to be the largest natural explosion in recorded history.
One of the assistant directors, Jindrich Polák, would go on to direct his own films and TV series that are now regarded as a classic Czech science fictions, like Voyage to the End of the Universe (1963), Tomorrow I'll Wake Up and Scald Myself with Tea (1977) or The Visitors (1983) among others.