Using first-principles density-functional calculations, gold monatomic wire
s are found to exhibit a zigzag shape which remains under tension, becoming
linens just before breaking. At room temperature they an found to spin, wh
ich explains the extremely long apparent interatomic distances shown by ele
ctron microscopy. The zigzag structure is stable if the tension is relieved
, the wire holding its chainlike shape even as a free-standing cluster. Thi
s unexpected metallic-wire stiffness stems from the transverse quantization
in the wire, as shown in a simple free electron model.