Atom dc = subtract(d,c); Atom abc = vectorProduct(ab,cb); Atom bcd = vectorProduct(bc,dc); Atom vecprod = vectorProduct(abc,bcd); double val = scalarProduct(cb,vecprod); if (val < 0.0)
otherTranslation = Calc.subtract(translation, screwTranslation); Atom hypot = Calc.vectorProduct(otherTranslation,rotationAxis); Calc.scaleEquals(hypot,.5/Math.tan(theta/2.0));