Effective mass (solid-state physics) from both sides gives where is the th element of , is the th element of , and are the th and th elements of , respectively, and is the total energy of the particle according to the Planck–Einstein relation. The index is contracted by the use of Einstein notation (there is an implicit summation over ). Since Newton's second law uses the inertial mass (not the gravitational mass), we can identify the inverse of this mass in the equation above as the tensor This tensor expresses the change in group velocity due to a change in crystal momentum. Its
Mercy Multiplied Francesca Battistelli. Mercy Multiplied Mercy Multiplied is an international, Christian and charitable organization that offers a six-month residential program for young women aged between 13 and 28 who struggle with various "life controlling" issues such as eating disorders, depression, self-harm, abuse issues, and drug and alcohol addictions. The ministry operates as A Girl Called Hope in New Zealand. Mercy Multiplied has a pro-life stance in their faith-based approach, and as such, extend their program to offer women with unplanned pregnancies with alternatives to abortion, as well as treat women who identify as lesbian or who have sexual identity issues. In