The killing of Russians - or more specifically Slavs, which includes a lot more than just Russians - is 100% true, your understanding is seriously mistaken. Slavs were considered Untermensch in Nazi ideology and were the second largest group of victims of the holocaust just after the Jews. The Nazi plan, which thankfully ‘only’ reached their initial stage of being carried out (murdering ~9 million people) was to exterminate most Slavic people, with the remainder to be reduced to illiterate chattel slavery under German colonists moving into their new lebensraum in the east.
The Generalplan Ost proposal offered various percentages of the conquered or colonized people who were targeted for removal and physical destruction; the net effect of which would be to ensure that the conquered territories would become German. In ten years’ time, the plan effectively called for the extermination, expulsion, Germanization or enslavement of most or all East and West Slavs living behind the front lines of East-Central Europe. The “Small Plan” was to be put into practice as the Germans conquered the areas to the east of their pre-war borders.[citation needed] After the war, under the “Big Plan”, more people in Eastern Europe were to be affected. [19][18][10] [12] In their place up to 10 million Germans would be settled in an extended “living space” (Lebensraum ). Because the number of Germans appeared to be insufficient to populate the vast territories of Central and Eastern Europe, the peoples judged to lie racially between the Germans and the Russians (Mittelschicht ), namely, Latvians and even Czechs, were also supposed to be resettled there.[25]
This is again 100% completely wrong. 3.3 million Soviet POWs were murdered by the Nazis, again this making them the second largest group of victims of the Holocaust. Note that this link is from the US Holocaust Memorial Museum: Nazi Persecution of Soviet Prisoners of War | Holocaust Encyclopedia (ushmm.org)
Soviets Viewed as Subhuman Enemies
Yet for Nazi Germany this attack was not an “ordinary” military operation. The war against the Soviet Union was a war of annihilation between German fascism and Soviet communism; a racial war between German “Aryans” and subhuman Slavs and Jews. From the very beginning this war of annihilation against the Soviet Union included the killing of prisoners of war (POWs) on a massive scale. In part, German officials excused their ill treatment and murder of Soviet POWs by pointing out that the Soviet Union was not a signatory to the Geneva Convention and its soldiers did not warrant the protection that the convention extended to prisoners of war. In reality, their reasons were more complex. German authorities viewed Soviet POWs as a particular threat, regarding them not only as Slavic subhumans but as part of the “Bolshevik menace” linked in Nazi ideology to the concept of a “Jewish conspiracy.”
Second Largest Group of Nazi Victims
The brutal treatment of Soviet POWs by the Germans violated every standard of warfare. Existing sources suggest that some 5.7 million Soviet army personnel fell into German hands during World War II. As of January 1945, the German army reported that only about 930,000 Soviet POWs remained in German custody. The German army released about one million Soviet POWs as auxiliaries of the German army and the SS. About half a million Soviet POWs had escaped German custody or had been liberated by the Soviet army as it advanced westward through eastern Europe into Germany. The remaining 3.3 million, or about 57 percent of those taken prisoner, were dead by the end of the war. Second only to the Jews, Soviet prisoners of war were the largest group of victims of Nazi racial policy.
The recruitment of Soviet prisoners into the Wehrmacht as auxiliaries occurred behind Hitler’s back and against his express orders. The name given to them, hiwis, short for Hilfswilliger or, in English, auxiliary volunteer is in itself a rather cruel joke. They were, for the most part, ‘volunteering’ because the other option was murder by starvation in Nazi POW camps.