"In this case, the molecules of the crystal are in the cis geometry – of groups pointing towards each other – and melt to an identical geometry in the absence of acid at 100 degrees Celsius.

Large, grainy crystals can form around foreign matter that ends up in your fudge, which can be something as imperceptibly tiny as bits of dust. Sugars that aren't completely melted into the ...

The other key component is a crystal called halide perovskite, which contains elements such as lead, bromine and iodine, alongside long molecules of carbon, hydrogen and nitrogen. The team melted ...