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 early 2008, Mercy Multiplied have attracted considerable media attention in Australia, followed by the United States and the United Kingdom, drawing criticism of their employment of unqualified staff, overall medical negligence, and the use of demonic deliverance in their approach to treatment. The company's rebranding efforts from Mercy Ministries to Mercy Multiplied, but also including the new brand A Girl Called Hope in New Zealand, were criticized as attempts to silence critics. Mercy Multiplied is endorsed by Joyce Meyer, who contributed "hundreds of thousands of dollars" in addition to providing teaching materials for the Mercy program and helping the St.